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Samarium compounds

From Wikipedia, the free encyclopedia
Samarium(III) acetate, a compound of samarium

Samarium compounds are compounds formed by the lanthanide metal samarium (Sm). Samarium most commonly occurs in the +3 oxidation state, as in Sm2O3, SmCl3 and Sm(NO3)3. The +2 oxidation state is unusually accessible for a lanthanide and gives rise to an extensive chemistry of divalent halides, chalcogenides, coordination compounds and organometallic compounds. Among these, samarium(II) iodide (SmI2) is widely used as a single-electron reducing agent in organic synthesis.

Samarium forms a broad range of binary compounds, including oxides, hydrides, halides, chalcogenides, borides, carbides, silicides and pnictides, as well as numerous coordination and organosamarium compounds. Several display unusual electronic behaviour associated with changes in samarium valence. Samarium(II) sulfide undergoes a pressure-induced transition from a black semiconducting state to a golden metallic state, while samarium hexaboride is an intermediate-valence Kondo insulator studied for its low-temperature electronic properties. Samarium compounds also have practical uses in organic synthesis, catalysis and optical materials, while samarium–cobalt intermetallic compounds are important high-temperature permanent-magnet materials.

Properties of samarium compounds

[edit]
Formula Colour Crystal system Space group No Pearson symbol a (pm) b (pm) c (pm) Z Density,
g/cm3
Sm silvery trigonal[1] R3m 166 hR9 362.9 362.9 2621.3 9 7.52
Sm silvery hexagonal[1] P63/mmc 194 hP4 362 362 1168 4 7.54
Sm silvery tetragonal[2] I4/mmm 139 tI2 240.2 240.2 423.1 2 20.46
SmO golden cubic[3] Fm3m 225 cF8 494.3 494.3 494.3 4 9.15
Sm2O3 trigonal[4] P3m1 164 hP5 377.8 377.8 594 1 7.89
Sm2O3 monoclinic[4] C2/m 12 mS30 1418 362.4 885.5 6 7.76
Sm2O3 cubic[5] Ia3 206 cI80 1093 1093 1093 16 7.1
SmH2 cubic[6] Fm3m 225 cF12 537.73 537.73 537.73 4 6.51
SmH3 hexagonal[7] P3c1 165 hP24 377.1 377.1 667.2 6
Sm2B5 gray monoclinic[8] P21/c 14 mP28 717.9 718 720.5 4 6.49
SmB2 hexagonal[9] P6/mmm 191 hP3 331 331 401.9 1 7.49
SmB4 tetragonal[10] P4/mbm 127 tP20 717.9 717.9 406.7 4 6.14
SmB6 cubic[11] Pm3m 221 cP7 413.4 413.4 413.4 1 5.06
SmB66 cubic[12] Fm3c 226 cF1936 2348.7 2348.7 2348.7 24 2.66
Sm2C3 cubic[13] I43d 220 cI40 839.89 839.89 839.89 8 7.55
SmC2 tetragonal[13] I4/mmm 139 tI6 377 377 633.1 2 6.44
SmF2 purple[14] cubic[15] Fm3m 225 cF12 587.1 587.1 587.1 4 6.18
SmF3 white[14] orthorhombic[15] Pnma 62 oP16 667.22 705.85 440.43 4 6.64
SmCl2 brown[14] orthorhombic[16] Pnma 62 oP12 756.28 450.77 901.09 4 4.79
SmCl3 yellow[14] hexagonal[15] P63/m 176 hP8 737.33 737.33 416.84 2 4.35
SmBr2 brown[14] orthorhombic[17] Pnma 62 oP12 797.7 475.4 950.6 4 5.72
SmBr3 yellow[14] orthorhombic[18] Cmcm 63 oS16 404 1265 908 2 5.58
SmI2 green[14] monoclinic P21/c 14 mP12
SmI3 orange[14] trigonal[19] R3 148 hR24 749 749 2080 6 5.24
SmN cubic[20] Fm3m 225 cF8 357 357 357 4 8.48
SmP cubic[21] Fm3m 225 cF8 576 576 576 4 6.3
SmAs cubic[22] Fm3m 225 cF8 591.5 591.5 591.5 4 7.23

Chalcogenides

[edit]

Oxides

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Samarium sesquioxide

The most stable oxide of samarium is the sesquioxide Sm2O3, which exists in several crystalline modifications. The trigonal form can be obtained by slow cooling from the melt. Because Sm2O3 has a high melting point of about 2345 °C, it is generally melted by induction heating using a radio-frequency coil rather than by direct heating. Crystals of the monoclinic modification can be grown from Sm2O3 powder by the flame-fusion (Verneuil) method, producing cylindrical boules several centimetres long and about one centimetre in diameter. These are transparent when pure and defect-free, but orange when defects are present. Heating the metastable trigonal modification to about 1900 °C converts it to the more stable monoclinic form.[4] A cubic modification of Sm2O3 has also been described.[5]

Samarium is one of the few lanthanides known to form a monoxide, SmO. This lustrous golden-yellow compound can be obtained by reducing Sm2O3 with samarium metal at about 1000 °C under pressures above 50 kbar; at lower pressures the reaction is incomplete. SmO crystallizes in the cubic rock salt structure.[3][23]

Other chalcogenides

[edit]

Samarium forms several sulfides in addition to SmS. The sesquisulfide Sm2S3, containing Sm3+, is polymorphic. The A- or α-modification is orthorhombic with space group Pnma, whereas the C- or γ-modification has a cubic, cation-deficient Th3P4-type structure with space group I43d. The former can be obtained by oxidation of SmCl2 with sulfur in a sodium chloride flux, while the latter has been prepared by reaction of the elements under related conditions.[24] A mixed-valence sulfide, Sm3S4, is also known. It adopts the Th3P4 structure and contains samarium in both the +2 and +3 oxidation states.[24]

The corresponding sesquiselenide Sm2Se3 is likewise polymorphic. Chemical-transport reactions have yielded red-brown crystals of a cation-deficient Th3P4-type modification with space group I43d, as well as black crystals of an orthorhombic U2S3-type modification with space group Pnma.[25] The trivalent telluride Sm2Te3 is also known.

The divalent monochalcogenides SmS, SmSe and SmTe crystallize in the cubic rock-salt structure and are narrow-gap semiconductors at ambient pressure. Their unusual electronic properties arise from the accessibility of the Sm2+ and Sm3+ configurations, and all three undergo pressure-induced changes toward metallic, intermediate-valence states.[26][27]

The transition is particularly abrupt in SmS. At room temperature it occurs at about 6.5 kbar and is accompanied by a change from the black semiconducting state to a golden, much more conductive state. The rock-salt symmetry is retained, but the unit-cell volume decreases by about 13.5%, reflecting the change from predominantly divalent samarium toward an intermediate-valence state.[26] Mechanical pressure produced by scratching or polishing can produce the same characteristic golden coloration at the surface. SmSe and SmTe undergo analogous but continuous electronic transitions over considerably broader and higher pressure ranges.[27] SmS additionally exhibits hysteresis: after compression, the semiconducting phase is recovered at a substantially lower pressure than that required to induce the metallic state.[28]

Halides

[edit]
Samarium trichloride hexahydrate

Samarium forms both trivalent and divalent binary halides. Reaction of the metal with the halogens gives the trihalides SmX3 (X = F, Cl, Br or I):[29]

2 Sm + 3 X2 → 2 SmX3

Their crystal structures vary across the series. SmF3 is orthorhombic, while SmCl3 adopts the hexagonal UCl3 structure type and SmBr3 the orthorhombic PuBr3 type.[15][30] Samarium(III) iodide belongs instead to the layered BiI3 structure type characteristic of the heavier lanthanide triiodides.[19]

The +2 oxidation state is considerably more accessible for samarium than for most lanthanides, and all four samarium dihalides SmF2, SmCl2, SmBr2 and SmI2 are known.[31] Reduction of the trihalides with samarium, lithium or sodium at about 700–900 °C gives the corresponding lower halides.[16] SmF2 crystallizes in the cubic fluorite structure, whereas SmCl2 and SmBr2 have orthorhombic structures.[15][16] The diiodide can also be prepared by heating SmI3, or by reaction of samarium metal with 1,2-diiodoethane in anhydrous tetrahydrofuran at room temperature:[32]

Sm + ICH2CH2I → SmI2 + CH2=CH2

The samarium–halogen systems also contain intermediate phases between the formal +2 and +3 compositions. In the fluoride system these include Sm3F7, Sm14F33 and Sm27F64.[15] Three closely spaced phases occur between SmBr2 and SmBr3, with compositions Sm6Br13, Sm11Br24 and Sm5Br11. Their structures are related to the fluorite structure and accommodate additional bromide ions in long-period superstructures.[33]

Several samarium halides are polymorphic under pressure or at elevated temperature. Compression of the usual monoclinic form of SmI2, followed by decompression, produces an orthorhombic PbCl2-type modification with a density of 5.90 g/cm3.[34] High-pressure treatment likewise produces a denser modification of SmI3, with a reported density of 5.97 g/cm3.[35]

Hydrides

[edit]

Samarium reacts directly with hydrogen to form non-stoichiometric hydrides of approximate composition SmH+2x. Hydrogen uptake is strongly dependent on the physical state of the metal: powdered samarium begins to absorb hydrogen rapidly at about 300–330 °C, whereas bulk samples may require temperatures up to about 525 °C. Compositions as hydrogen-rich as approximately SmH2.63 have been obtained by direct hydrogenation.[36] The hydrides are sensitive to air and can partially decompose to samarium oxide under ambient conditions.[36]

The samarium–hydrogen system contains several distinct phases between the nominal dihydride and trihydride compositions. The fluorite-related cubic phase extends approximately over SmH1.95−2.30, while a hydrogen-rich hexagonal, tysonite-related phase occurs around SmH2.82−2.90. An intermediate phase, Sm3H7, has a tetragonally distorted fluorite-related structure analogous to that of Sm3F7. Similar phase relationships occur in the corresponding deuterides.[37] The structural chemistry follows the general hydride–fluoride analogy found among lanthanides; unlike europium, however, samarium is readily oxidized from Sm2+ toward Sm3+ as the hydrogen content increases.[38]

At elevated pressure, samarium trihydride undergoes a reversible transformation from its ambient-pressure hexagonal structure to a cubic high-pressure phase.[39] Much more hydrogen-rich phases have also been obtained at megabar pressures. In 2026, laser heating samarium with ammonia borane in diamond-anvil cells produced phases assigned as SmH9, SmH6, SmH4, SmH3, SmH2 and hydrogen-deficient SmH−2x. The higher hydrides were metallic under the conditions studied, but no superconducting transition was observed.[40]

Borides

[edit]

Samarium forms several binary borides spanning a wide range of boron content. Early phase-equilibrium studies of the Sm–B system identified a samarium-rich phase of approximate composition SmB2, together with SmB4, SmB6 and the boron-rich phase SmB66.[11] The tetraboride and hexaboride have measurable homogeneity ranges, and the hardness of the phases generally increases with increasing boron content.[11] A further boride, Sm2B5, has also been structurally characterized.[8]

SmB2 is difficult to obtain under ordinary conditions because more boron-rich phases are preferentially formed. It has been synthesized at high pressure and high temperature and adopts the hexagonal AlB2 structure type, with lattice parameters a = 0.3310 nm and c = 0.4019 nm.[9] SmB4 crystallizes in the tetragonal ThB4 structure type. It undergoes antiferromagnetic ordering near 25 K, with a second low-temperature anomaly near 7 K.[41]

Powder mixtures of samarium oxide and boron can be sintered under vacuum to give mixtures of boride phases, whose proportions depend on the starting composition.[11] Larger crystals of SmB4, SmB6 and SmB66 can be produced by arc or zone melting, taking advantage of their different melting and crystallization behaviour. These borides are dark, hard and brittle, with hardness generally increasing with boron content.[11]

Samarium hexaboride

[edit]

Samarium hexaboride, SmB6, crystallizes in the cubic CaB6 structure type, in which B6 octahedra form a three-dimensional boron framework surrounding the samarium atoms. It is an intermediate valence compound: the samarium 4f configuration fluctuates between states conventionally described as Sm2+ and Sm3+, giving an average valence of about +2.6 near room temperature rather than distinct crystallographic Sm2+ and Sm3+ sites.[42]

At high temperature SmB6 has comparatively conductive behaviour, but on cooling the hybridization of localized 4f states with conduction states opens a narrow gap and the bulk becomes insulating. It is therefore a prototypical Kondo insulator. Spectroscopic measurements find energy scales of several to several tens of millielectronvolts associated with the hybridization gap, depending on the experimental method.[43][42] The decrease in the number of mobile bulk charge carriers is accompanied by a marked rise in thermal conductivity at low temperature, with a maximum near 15 K.[44]

Below a few kelvin, the electrical resistance of SmB6 does not continue to increase as expected for a conventional bulk insulator, but instead approaches a plateau associated with electrically conducting surface states. Transport and photoemission experiments have reported surface states consistent with a topological origin, and SmB6 is widely studied as a candidate topological Kondo insulator.[45][46][47][42] Some aspects of the low-temperature bulk state nevertheless remain unresolved, including the origin of reported in-gap states and quantum oscillations.[42]

Carbides and silicides

[edit]

Samarium forms several binary carbides. They can be prepared by high-temperature reaction of samarium metal with graphite under an inert atmosphere; the products are sensitive to air and are generally handled under inert conditions.[13] The best established phases are samarium dicarbide, SmC2, and the sesquicarbide, conventionally written Sm2C3. SmC2 is a brittle solid with a metallic golden lustre and crystallizes in the tetragonal calcium carbide structure, space group I4/mmm, with lattice parameters of about a = 0.376 nm and c = 0.634 nm.[13][48]

The sesquicarbide has the cubic Pu2C3-type structure. More detailed phase-equilibrium studies found it to be appreciably carbon-deficient rather than exactly stoichiometric Sm2C3, with a composition range approximately SmC1.36–SmC1.45. Its composition also varies with temperature.[49] Earlier studies also reported a samarium-rich carbide Sm3C with a cubic Fe4N-type structure. Its existence as a binary carbide has subsequently been disputed: reinvestigation of the Sm–C–O system failed to reproduce binary Sm3C and instead identified a samarium oxycarbide with similar structural parameters.[49]

Samarium also forms a series of silicides. The established binary phases in the Sm–Si system include Sm5Si3, Sm5Si4, SmSi, Sm3Si5 and SmSi2.[50] They can be prepared by high-temperature reaction or annealing of mixtures of the elements. Samarium monosilicide adopts an orthorhombic FeB-type structure,[51] while Sm5Si3 belongs to the hexagonal Mn5Si3 structure type. Compounds at the 5:4 and 5:3 compositions have also been studied together with the corresponding rare-earth germanides.[52]

Samarium disilicide, SmSi2, occurs in two principal crystalline modifications. The low-temperature α-form is orthorhombic, whereas the β-form is tetragonal with the α−ThSi2 structure; the transformation occurs at about 380 °C. SmSi2 melts congruently at approximately 1800 °C.[50]

Pnictides

[edit]

Samarium forms the complete series of equiatomic monopnictides SmN, SmP, SmAs, SmSb and SmBi. All crystallize in the cubic rock salt structure, with samarium predominantly in the +3 oxidation state, although their electronic and magnetic properties vary substantially across the series.[53]

Samarium nitride, SmN, can be prepared by direct reaction of samarium metal with nitrogen. It has the rock-salt structure with a lattice parameter of 0.50481 nm.[54] SmN is a ferromagnetic semiconductor with a Curie temperature of about 27 K. Its ordered magnetic moment is unusually small because the orbital and spin contributions of the Sm3+ 4f electrons are oppositely directed and largely cancel one another.[55]

Samarium monophosphide, SmP, is a semiconductor with a band gap of about 1.1 eV. It can be prepared by annealing a mixture of samarium and phosphorus in an evacuated ampoule at about 1100 °C.[21] SmAs is likewise a rock-salt monopnictide. Its electronic state is closely related to the valence-instability characteristic of samarium compounds: in solid solutions of SmAs with divalent SmSe, the average samarium valence changes continuously from predominantly Sm2+ to Sm3+ as the arsenide content is increased.[22]

The heavier monopnictides SmSb and SmBi are low-carrier-density semimetals and order antiferromagnetically at low temperatures.[53] SmSb has a Néel temperature of about 2.1 K and exhibits Kondo-like behaviour in its low-temperature specific heat and magnetic susceptibility.[56] SmBi also has the rock-salt structure and undergoes antiferromagnetic ordering at about 9 K.[57]

Other stoichiometries occur particularly among the heavier pnictides. Samarium diantimonide, SmSb2, is the prototype of the orthorhombic SmSb2 structure type (space group No. 64). Its structure contains two-dimensional rectangular nets of antimony atoms separated by samarium-containing layers, resulting in strongly anisotropic electronic properties.[58]

Other inorganic compounds

[edit]
Samarium sulfate, Sm2(SO4)3

Samarium(III) hydroxide, Sm(OH)3, can be precipitated from aqueous Sm3+ solutions with hydroxide ions. It crystallizes in a hexagonal structure and can be converted by calcination to Sm2O3 while largely retaining the morphology of the hydroxide precursor.[59] Samarium oxyhydroxide, SmOOH, is also known. It crystallizes in the monoclinic space group P21/m, with lattice parameters a = 0.4356 nm, b = 0.3766 nm, c = 0.6139 nm and β = 108.464°. Millimetre-scale yellowish crystals have been grown from molten alkali hydroxides.[60]

Several common oxyanion salts of Sm3+ form hydrated crystals. Samarium(III) nitrate is commonly encountered as the hexahydrate Sm(NO3)3·6H2O. On heating, it loses water in several stages and subsequently forms Sm(OH)(NO3)2 and crystalline SmO(NO3) before decomposition to Sm2O3 at about 520 °C.[61]

Samarium(III) oxalate precipitates readily from aqueous Sm3+ solutions and can be isolated as the decahydrate Sm2(C2O4)3·10H2O. The hydrate crystallizes in the monoclinic space group P21/c; transparent yellowish single crystals have been grown by gel diffusion.[62] It loses its water on heating and ultimately decomposes to samarium(III) oxide; the anhydrous oxalate is thermally unstable and decomposition to the oxide is complete at about 645 °C.[61]

Hydrated samarium(III) sulfates are also known. The pentahydrate Sm2(SO4)3(H2O)5 crystallizes in the monoclinic space group C2/c; each samarium centre is coordinated by eight oxygen atoms from sulfate groups and water molecules, and the sulfate groups link the samarium coordination polyhedra into a three-dimensional framework.[63]

Samarium orthophosphate, SmPO4, has the monoclinic monazite structure, space group P21/n. It can be prepared by precipitation from aqueous samarium and phosphate solutions followed by heating, as well as by hydrothermal and solid-state methods.[64]

Samarium(III) acetate, Sm(CH3COO)3, also forms several hydrates. The tetrahydrate begins to dehydrate at about 70 °C, passing through lower hydrates. Anhydrous samarium acetate is strongly hygroscopic and on further heating decomposes through oxycarbonate-containing intermediates to samarium(III) oxide.[65]

Coordination compounds

[edit]

Like other lanthanides, samarium forms predominantly ionic coordination compounds with relatively high coordination numbers and a preference for hard donor atoms, especially oxygen. Sm3+ is the more common oxidation state, but the accessibility of Sm2+ gives samarium an unusually extensive low-valent coordination chemistry. The coordination sphere can vary substantially with ligand size and solvent.[66]

An example of a Sm3+ macrocyclic complex is [SmI3(dibenzo−−18crown−6)], obtained by reaction of samarium(III) iodide with dibenzo-18-crown-6 in acetonitrile. The samarium ion lies within the crown-ether cavity and is nine-coordinate, bonded to three iodide ions and all six oxygen atoms of the crown ether.[67]

The coordination chemistry of Sm2+ is especially important because it strongly affects the properties of samarium(II) iodide. Crystallization from tetrahydrofuran gives SmI2(THF)5, in which samarium is seven-coordinate with a pentagonal-bipyramidal environment: the two iodide ligands occupy the axial positions and five THF oxygen atoms form the equatorial plane. Related mixed-solvent complexes SmI2(DME)2(THF) and SmI2(DME)(THF)3 have the same overall seven-coordinate arrangement.[68] The coordination environment is highly sensitive to additives: X-ray absorption studies of SmI2 in THF–water mixtures showed that addition of at least eight equivalents of water leads to dissociation of the Sm–I interactions and formation of hydrated Sm2+ species.[69]

More elaborate ligands can stabilize discrete low-valent complexes. β-Diketiminate ligands, for example, give Sm2+ iodide complexes whose aggregation depends strongly on the amount of coordinated THF: removal of solvent from [Sm(Nacnac)I(THF)2] produces di-, tri- and tetranuclear species, while reaction of solvent-free SmI2 with two equivalents of the ligand gives mononuclear [Sm(Nacnac)2].[70]

Organosamarium compounds

[edit]
Crystals of a substituted samarium cyclopentadienyl complex

Cyclopentadienyl complexes

[edit]

Samarium forms both Sm3+ and Sm2+ cyclopentadienyl complexes. The classical trivalent compound Sm(C5H5)3 and its chlorinated derivatives Sm(C5H5)2Cl and Sm(C5H5)Cl2 can be prepared by reacting samarium trichloride with NaC5H5 in tetrahydrofuran. Unlike many simple lanthanide cyclopentadienides, Sm(C5H5)3 forms a polymeric structure in which some cyclopentadienyl ligands bridge neighbouring samarium centres through η1 or η2 interactions.[71] Sm(C5H5)2Cl is dimeric, with two bridging chloride ligands; the bridging groups can be replaced by iodide, hydride and other ligands.[72]

The cyclopentadienyl ligand can also be replaced by related aromatic ligands. Known examples include the indenyl compound Sm(C9H7)3 and the cyclooctatetraenyl complex KSm(η(8)−C8H8)2, whose sandwich structure is related to that of uranocene. Divalent samarium also forms Sm(C5H5)2, a volatile solid in which the two cyclopentadienyl rings are not parallel but are tilted by about 40°.[72]

In 1981, (C5Me5)2Sm(THF)2 was isolated as the first soluble organometallic Sm2+ complex, containing the bulky pentamethylcyclopentadienyl ligand (Cp*). It was the first soluble organometallic Sm2+ complex and provided access to the strong reducing chemistry of divalent samarium in a molecular organometallic environment.[73] The unsolvated complex (C5Me5)2Sm, often called decamethylsamarocene, was isolated three years later as a monomeric bent metallocene.[74] Reduction of dinitrogen by this complex subsequently gave [(C5Me5)2Sm]2N2, the first crystallographically characterized dinitrogen complex of an f-block element.[75]

σ-Bonded compounds

[edit]

Samarium also forms compounds containing localized Sm–C σ bonds. Salt-metathesis reactions in tetrahydrofuran or diethyl ether can give alkyl and aryl derivatives of Sm3+:[72]

SmCl3 + 3 LiR → SmR3 + 3 LiCl

and bulky alkyl ligands can be introduced from organolithium reagents:

Sm(OR)3 + 3 LiCH(SiMe3)2 → Sm{CH(SiMe3)2}3 + 3 LiOR

where R is a hydrocarbon group and Me denotes methyl. Steric bulk is important because simple lanthanide alkyls frequently undergo aggregation or decomposition.

Well-defined σ-bonded derivatives can also be obtained from divalent metallocenes. Reaction of (C5Me5)2Sm(THF)2 with trimethylaluminium gives samarium methyl compounds, including the monomeric Sm3+ complex (C5Me5)2SmMe(THF) and a methyl-bridged Sm–Al dimer.[76]

Transient organosamarium compounds are also central to the organic chemistry of SmI2. Successive one-electron reduction of an alkyl halide can convert an initially formed carbon radical into an organosamarium species, which can then react with electrophiles. Such intermediates participate in samarium-mediated Barbier, Grignard-type, Reformatsky and aldol reactions and can tolerate functional groups that are incompatible with more strongly basic lithium- or magnesium-based organometallic reagents.[77]

Alloys and intermetallic compounds

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Samarium forms numerous intermetallic compounds with transition metals. The samarium–cobalt system is particularly rich: binary phases reported across the composition range include Sm3Co, Sm9Co4, SmCo2, SmCo3, Sm2Co7, SmCo5 and Sm2Co17.[78] Many rare-earth–transition-metal structures in this composition range can be related structurally to the hexagonal CaCu5 structure by ordered replacement of rare-earth atoms by pairs of transition-metal atoms.[79]

Samarium–cobalt intermetallics

[edit]

The most prominent samarium–cobalt compounds are SmCo5 and Sm2Co17, which form the structural basis of commercially important samarium–cobalt permanent magnets. SmCo5 crystallizes in the hexagonal CaCu5 structure type, space group P6/mmm, in which samarium occupies one crystallographic site and cobalt occupies two nonequivalent sites.[79] It is strongly ferromagnetic and has a Curie temperature above 1000 K; neutron-diffraction measurements give a Curie temperature of about 1020 K.[80]

The structures of the cobalt-richer phases can be described in relation to SmCo5 by replacing samarium atoms with pairs of cobalt atoms, often termed cobalt "dumbbells".[79] Sm2Co17 commonly adopts the rhombohedral Th2Zn17 structure at lower temperatures, while hexagonal Th2Ni17-type and disordered TbCu7-related structures can be stabilized depending on temperature, composition and processing conditions.[81]

Commercial 2:17-type samarium–cobalt magnets are not usually simple binary Sm2Co17, but contain substantial amounts of iron, copper and zirconium. Heat treatment produces a cellular microstructure consisting principally of rhombohedral 2:17-type cells separated by SmCo5-type boundary regions, together with zirconium-rich lamellae. This microstructure is responsible for the high coercivity of the material.[82]

Other intermetallic compounds

[edit]

Samarium also forms binary intermetallic compounds with other transition metals. SmFe2 is a Laves phase that exhibits large negative magnetostriction. Although it was historically assigned a cubic structure, high-resolution diffraction studies found a trigonal structure with space group R3m at room temperature, transforming to an orthorhombic phase on cooling.[83]

The samarium–nickel system contains several compounds, including SmNi, SmNi2, SmNi3, Sm2Ni7, Sm5Ni19, SmNi5 and Sm2Ni17.[84] SmNi5 crystallizes in the same hexagonal CaCu5 structure type as SmCo5, with space group P6/mmm, but has quite different magnetic properties and a much lower Curie temperature of about 29 K.[85]

Applications

[edit]
Barbier reaction using SmI2

Samarium(II) iodide is widely used as a single-electron reducing agent in organic synthesis. Its reduction potential and selectivity can be modified substantially by the choice of solvent and additives, allowing reductions of carbonyl compounds, halides and other functional groups as well as carbon–carbon bond-forming reactions. SmI2-mediated transformations include Barbier, Reformatsky, aldol, pinacol and radical cyclization reactions, and the reagent has been used extensively in the total synthesis of complex natural products.[77][86] Although it is usually employed stoichiometrically, catalytic processes in which Sm2+ is regenerated during the reaction have also been developed.[87]

Samarium–cobalt intermetallic compounds are used as high-performance permanent magnet materials. The principal families are based on SmCo5 and Sm2Co17, with commercial 2:17-type magnets generally containing additional iron, copper and zirconium. Their high Curie temperatures, thermal stability and comparatively good corrosion resistance make Sm–Co magnets particularly suitable for applications requiring magnetic performance at temperatures above those normally tolerated by Nd–Fe–B magnets. They are consequently used in aerospace systems, sensors, electrical machinery and microwave equipment.[82]

Samarium(III) oxide has been investigated as a heterogeneous catalyst, particularly for the oxidative coupling of methane to ethane and ethylene. In an early comparison of thirty metal oxides, Sm2O3 showed high activity and selectivity toward C2 hydrocarbons, and both undoped and alkali-promoted samarium oxides have subsequently been studied for this reaction.[88]

Compounds of Sm3+ are also used to introduce samarium into optical materials. The characteristic 4f–4f transitions of Sm3+ give orange to red luminescence, and samarium-doped phosphate and other oxide glasses have been investigated as laser-active materials.[89] Sm3+-activated phosphors, which commonly emit near 600 nm, have likewise been investigated for orange-red components in solid-state lighting and other optical devices.[90]

Samarium(II) sulfide has attracted interest as a pressure-sensitive and switchable material because its pressure-induced black-to-golden transition is accompanied by large changes in electrical and optical properties. SmS has been used in strain-gauge devices, while thin films have been investigated for pressure sensing, non-volatile memory, infrared detection and thermoelectric or thermovoltaic devices. Many of these proposed applications remain limited by difficulties in preparing stable, stoichiometric SmS films with the required samarium oxidation state.[26]

Samarium hexaboride is primarily of interest as a condensed-matter research material. Its low-temperature insulating bulk and conducting surface states have made it an extensively studied example of a Kondo insulator and a candidate topological Kondo insulator.[91]

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See also

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References

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  1. 1 2 Shi, N.; Fort, D. (1985). "Preparation of samarium in the double hexagonal close packed form". Journal of the Less Common Metals. 113 (2): 21. doi:10.1016/0022-5088(85)90294-2.
  2. ↑ Vohra, Y.; Akella, Jagannadham; Weir, Sam; Smith, Gordon S. (1991). "A new ultra-high pressure phase in samarium". Physics Letters A. 158 (1–2): 89. Bibcode:1991PhLA..158...89V. doi:10.1016/0375-9601(91)90346-A.
  3. 1 2 Leger, J.; Yacoubi, N.; Loriers, J. (1981). "Synthesis of rare earth monoxides". Journal of Solid State Chemistry. 36 (3): 261. Bibcode:1981JSSCh..36..261L. doi:10.1016/0022-4596(81)90436-9.
  4. 1 2 3 Gouteron, J.; Michel, D.; Lejus, A. M.; Zarembowitch, J. (1981). "Raman spectra of lanthanide sesquioxide single crystals: Correlation between A and B-type structures". Journal of Solid State Chemistry. 38 (3): 288. Bibcode:1981JSSCh..38..288G. doi:10.1016/0022-4596(81)90058-X.
  5. 1 2 Taylor, D. (1984). "Thermal expansion data: III. Sesquioxides, M2O3, with the corundum and the A-, B- and C-M2O3 structures". British Ceramic Transactions and Journal. 83: 92–98.
  6. ↑ Daou, J.; Vajda, P.; Burger, J. (1989). "Low temperature thermal expansion in SmH2+x". Solid State Communications. 71 (12): 1145. Bibcode:1989SSCom..71.1145D. doi:10.1016/0038-1098(89)90728-X.
  7. ↑ Dolukhanyan, S. (1997). "Synthesis of novel compounds by hydrogen combustion". Journal of Alloys and Compounds. 253–254: 10. doi:10.1016/S0925-8388(96)03071-X.
  8. 1 2 Zavalii, L. V.; Kuz'ma, Yu. B.; Mikhalenko, S. I. (1990). "Sm2B5 boride and its structure". Soviet Powder Metallurgy and Metal Ceramics. 29 (6): 471. doi:10.1007/BF00795346. S2CID 138416728.
  9. 1 2 Cannon, John F.; Cannon, David M.; Hall, H. Tracy (1977). "High pressure syntheses of SmB2 and GdB12". Journal of the Less Common Metals. 56 (1): 83–90. doi:10.1016/0022-5088(77)90221-1.
  10. ↑ Etourneau, J.; Mercurio, J.; Berrada, A.; Hagenmuller, P.; Georges, R.; Bourezg, R.; Gianduzzo, J. (1979). "The magnetic and electrical properties of some rare earth tetraborides". Journal of the Less Common Metals. 67 (2): 531. doi:10.1016/0022-5088(79)90038-9.
  11. 1 2 3 4 5 Solovyev, G. I.; Spear, K. E. (1972). "Phase Behavior in the Sm-B System". Journal of the American Ceramic Society. 55 (9): 475–479. doi:10.1111/j.1151-2916.1972.tb11344.x.
  12. ↑ Schwetz, K.; Ettmayer, P.; Kieffer, R.; Lipp, A. (1972). "Über die Hektoboridphasen der Lanthaniden und Aktiniden". Journal of the Less Common Metals. 26: 99. doi:10.1016/0022-5088(72)90012-4.
  13. 1 2 3 4 Spedding, F. H.; Gschneidner, K.; Daane, A. H. (1958). "The Crystal Structures of Some of the Rare Earth Carbides". Journal of the American Chemical Society. 80 (17): 4499–4503. Bibcode:1958JAChS..80.4499S. doi:10.1021/ja01550a017.
  14. 1 2 3 4 5 6 7 8 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1241. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
  15. 1 2 3 4 5 6 Greis, O. (1978). "Über neue Verbindungen im system SmF2_SmF3". Journal of Solid State Chemistry. 24 (2): 227. Bibcode:1978JSSCh..24..227G. doi:10.1016/0022-4596(78)90013-0.
  16. 1 2 3 Meyer, G.; Schleid, T. (1986). "The metallothermic reduction of several rare-earth trichlorides with lithium and sodium". Journal of the Less Common Metals. 116: 187. doi:10.1016/0022-5088(86)90228-6.
  17. ↑ Bärnighausen, H. (1973). Revue de chimie minérale. 10: 77–92.{{cite journal}}: CS1 maint: untitled periodical (link)
  18. ↑ Zachariasen, W. H. (1948). "Crystal chemical studies of the 5f-series of elements. I. New structure types". Acta Crystallographica. 1 (5): 265. Bibcode:1948AcCry...1..265Z. doi:10.1107/S0365110X48000703.
  19. 1 2 Asprey, L. B.; Keenan, T. K.; Kruse, F. H. (1964). "Preparation and Crystal Data for Lanthanide and Actinide Triiodides". Inorganic Chemistry. 3 (8): 1137–1141. doi:10.1021/ic50018a015.
  20. ↑ Brown, R.; Clark, N. J. (1974). "Composition limits and vaporization behaviour of rare earth nitrides". Journal of Inorganic and Nuclear Chemistry. 36 (11): 2507. doi:10.1016/0022-1902(74)80462-8.
  21. 1 2 Meng, J.; Ren, Yufang (1991). "Studies on the electrical properties of rare earth monophosphides". Journal of Solid State Chemistry. 95 (2): 346. Bibcode:1991JSSCh..95..346M. doi:10.1016/0022-4596(91)90115-X.
  22. 1 2 Beeken, R.; Schweitzer, J. (1981). "Intermediate valence in alloys of SmSe with SmAs". Physical Review B. 23 (8): 3620. Bibcode:1981PhRvB..23.3620B. doi:10.1103/PhysRevB.23.3620.
  23. ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1239. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
  24. 1 2 Lissner, Falk; Schleid, Thomas (1992). "Über Sulfide und Oxidsulfide des Samariums / On Sulfides and Oxysulfides of Samarium". Zeitschrift für Naturforschung B. 47 (11): 1614–1620. doi:10.1515/znb-1992-1116.
  25. ↑ Grundmeier, Thorsten; Urland, Werner (1995). "Zur Polymorphie von Sm2Se3". Zeitschrift für anorganische und allgemeine Chemie. 621 (11): 1977–1979. doi:10.1002/zaac.19956211125.
  26. 1 2 3 Sousanis, Andreas; Smet, Philippe F.; Poelman, Dirk (2017). "Samarium Monosulfide (SmS): Reviewing Properties and Applications". Materials. 10 (8): 953. doi:10.3390/ma10080953. PMC 5578319. PMID 28813006.
  27. 1 2 Jayaraman, A.; Narayanamurti, V.; Bucher, E.; Maines, R. G. (1970). "Continuous and Discontinuous Semiconductor-Metal Transition in Samarium Monochalcogenides Under Pressure". Physical Review Letters. 25 (20): 1430–1433. Bibcode:1970PhRvL..25.1430J. doi:10.1103/PhysRevLett.25.1430.
  28. ↑ Emsley, John (2001). "Samarium". Nature's Building Blocks: An A–Z Guide to the Elements. Oxford: Oxford University Press. pp. 371–374. ISBN 0-19-850340-7.
  29. ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 1236, 1241. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
  30. ↑ Goerigk, Falk; Schleid, Thomas (2019). "Composition and Crystal Structure of SmSb2O4Cl Revisited – and the Analogy of Sm1.5Sb1.5O4Br". Zeitschrift für anorganische und allgemeine Chemie. 645: 1079–1084. doi:10.1002/zaac.201900139.
  31. ↑ Simon, Arndt; Mattausch, Hansjürgen (2013). "Low-Valence Compounds of the Lanthanoids". Comprehensive Inorganic Chemistry II. Elsevier. pp. 535–581. doi:10.1016/B978-0-08-097774-4.00224-2.
  32. ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1240. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
  33. ↑ Baernighausen, H.; Haschke, John M. (1978). "Compositions and crystal structures of the intermediate phases in the samarium-bromine system". Inorganic Chemistry. 17 (1): 18–21. doi:10.1021/ic50179a005.
  34. ↑ Beck, H. P. (1979). "Hochdruckmodifikationen der Diiodide von Sr., Sm und Eu. Eine neue PbCl2-Variante?". Zeitschrift für anorganische und allgemeine Chemie. 459 (1): 81. Bibcode:1979ZAACh.459...81B. doi:10.1002/zaac.19794590108.
  35. ↑ Beck, H. P.; Gladrow, E. (1979). "Zur Hochdruckpolymorphie der Seltenerd-Trihalogenide". Zeitschrift für anorganische und allgemeine Chemie. 453 (1): 79. Bibcode:1979ZAACh.453...79B. doi:10.1002/zaac.19794530610.
  36. 1 2 Christodoulou, Chris N.; Takeshita, Takuo (1992). "Reaction of samarium with hydrogen and nitrogen; samarium oxides". Journal of Alloys and Compounds. 190 (1): 99–106. doi:10.1016/0925-8388(92)90183-A.
  37. ↑ Greis, Ortwin; Knappe, Peter; Müller, Horst (1981). "Phase relationships in the systems SmH2–SmH3 and SmD2–SmD3". Journal of Solid State Chemistry. 39 (1): 49–55. doi:10.1016/0022-4596(81)90302-9.
  38. ↑ Kohlmann, Holger (2010). "Solid-State Structures and Properties of Europium and Samarium Hydrides". European Journal of Inorganic Chemistry. 2010 (18): 2582–2593. doi:10.1002/ejic.201000107.
  39. ↑ Palasyuk, T.; Tkacz, M. (2007). "Pressure-induced structural phase transition in rare-earth trihydrides. Part II. SmH3 and compressibility systematics". Solid State Communications. 141 (5): 302–305. doi:10.1016/j.ssc.2006.06.045.
  40. ↑ Ma, Liang; Shan, Pengfei; Bi, Jingkai; Xu, Wenfei; Jiang, Sheng; Zhang, Lili; Yang, Pengtao; Wang, Bosen; Sun, Jianping; Guo, Haizhong; Cheng, Jinguang (2026). "High-Pressure Synthesis of Samarium Hydrides". Annalen der Physik. 538 (1): e00545. doi:10.1002/andp.202500545.{{cite journal}}: CS1 maint: article number as page number (link)
  41. ↑ Knyazev, Yu. V.; Kuz'min, Yu. I.; Kuz'min, M. D. (2015). "Peculiarities of electronic, phonon and magnon subsystems of lanthanum and samarium tetraborides". Journal of Alloys and Compounds. 646: 906–911. doi:10.1016/j.jallcom.2015.06.101.
  42. 1 2 3 4 Li, Lu; Sun, Kai; Kurdak, Cagliyan; Allen, J. W. (2020). "Emergent mystery in the Kondo insulator samarium hexaboride". Nature Reviews Physics. 2: 463–479. doi:10.1038/s42254-020-0210-8.
  43. ↑ Nyhus, P.; Cooper, S.; Fisk, Z.; Sarrao, J. (1995). "Light scattering from gap excitations and bound states in SmB6". Physical Review B. 52 (20): R14308–R14311. Bibcode:1995PhRvB..5214308N. doi:10.1103/PhysRevB.52.R14308. PMID 9980746.
  44. ↑ Sera, M.; Kobayashi, S.; Hiroi, M.; Kobayashi, N.; Kunii, S. (1996). "Thermal conductivity of RB6 (R=Ce, Pr, Nd, Sm, Gd) single crystals". Physical Review B. 54 (8): R5207–R5210. Bibcode:1996PhRvB..54.5207S. doi:10.1103/PhysRevB.54.R5207. PMID 9986570.
  45. ↑ Kim, D. J.; Thomas, S.; Grant, T.; Botimer, J.; Fisk, Z.; Xia, Jing (2013). "Surface Hall Effect and Nonlocal Transport in SmB6: Evidence for Surface Conduction". Scientific Reports. 3: 3150. arXiv:1211.6769. Bibcode:2013NatSR...3.3150K. doi:10.1038/srep03150. PMC 3818682. PMID 24193196.
  46. ↑ Zhang, Xiaohang; Butch, N. P.; Syers, P.; Ziemak, S.; Greene, Richard L.; Paglione, Johnpierre (2013). "Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6". Physical Review X. 3 (1) 011011. arXiv:1211.5532. Bibcode:2013PhRvX...3a1011Z. doi:10.1103/PhysRevX.3.011011. S2CID 53638956.
  47. ↑ Wolgast, Steven; Kurdak, Cagliyan; Sun, Kai; Allen, J. W.; Kim, Dae-Jeong; Fisk, Zachary (2013). "Low-temperature surface conduction in the Kondo insulator SmB6". Physical Review B. 88 (18) 180405. arXiv:1211.5104. Bibcode:2013PhRvB..88r0405W. doi:10.1103/PhysRevB.88.180405. S2CID 119242604.
  48. ↑ Vidhya, R.; Antony, M. P.; Vasudeva Rao, P. R. (2003). "Enthalpy and Gibbs energy of formation of samarium dicarbide". Journal of Nuclear Materials. 322 (2–3): 189–194. doi:10.1016/S0022-3115(03)00326-X.
  49. 1 2 Haschke, John M.; Deline, Thomas A. (1982). "Vaporization and thermodynamic properties of samarium dicarbide and sub-stoichiometric disamarium tricarbide". The Journal of Chemical Thermodynamics. 14 (11): 1019–1028. doi:10.1016/0021-9614(82)90144-6.
  50. 1 2 Gokhale, A. B.; Abbaschian, G. J. (1988). "The Si-Sm (Silicon-Samarium) system". Bulletin of Alloy Phase Diagrams. 9 (5): 582–585. doi:10.1007/BF02881960.
  51. ↑ Gladyshevskii, E. I.; Kripyakevich, P. I. (1965). "Monosilicides of rare earth metals and their crystal structures". Journal of Structural Chemistry. 5 (6): 789. Bibcode:1965JStCh...5..789G. doi:10.1007/BF00744231. S2CID 93941853.
  52. ↑ Smith, G. S.; Tharp, A. G.; Johnson, W. (1967). "Rare earth–germanium and –silicon compounds at 5:4 and 5:3 compositions". Acta Crystallographica. 22 (6): 940. Bibcode:1967AcCry..22..940S. doi:10.1107/S0365110X67001902.
  53. 1 2 Duan, Xu; Wu, Fan; Chen, Jia; Zhang, Peiran; Liu, Yang; Yuan, Huiqiu; Cao, Chao (2018). "Tunable electronic structure and topological properties of LnPn (Ln=Ce, Pr, Sm, Gd, Yb; Pn=Sb, Bi)". Communications Physics. 1: 71. doi:10.1038/s42005-018-0074-8.
  54. ↑ Eick, H. A.; Baenziger, N. C.; Eyring, L. (1956). "The Preparation, Crystal Structure and Some Properties of SmN, EuN and YbN". Journal of the American Chemical Society. 78 (23): 5987–5989. doi:10.1021/ja01604a006.
  55. ↑ McNulty, J. F.; Ruck, B. J.; Trodahl, H. J. (2016). "On the ferromagnetic ground state of SmN". Physical Review B. 93 (5): 054413. doi:10.1103/PhysRevB.93.054413.{{cite journal}}: CS1 maint: article number as page number (link)
  56. ↑ Ozeki, S.; Kwon, Y.-S.; Haga, Y.; Suzuki, T.; Kido, G.; Kasuya, T. (1991). "De Haas-van Alphen effect in SmSb". Physica B: Condensed Matter. 169: 499–500. doi:10.1016/0921-4526(91)90295-P.
  57. ↑ Sakhya, Anup Pradhan; Pramanik, Arindam; Pandeya, Ram Prakash; Datta, Sawani; Singh, Abhishek; Thamizhavel, A.; Maiti, Kalobaran (2020). "Preparation, characterization and x-ray photoemission spectroscopy study of a correlated semimetal, SmBi". AIP Conference Proceedings. 2265: 030369. doi:10.1063/5.0017127.
  58. ↑ Benavides, Katherine A.; Oswald, Iain W. H.; Chan, Julia Y. (2018). "Casting a Wider Net: Rational Synthesis Design of Low-Dimensional Bulk Materials". Accounts of Chemical Research. 51 (1): 12–20. doi:10.1021/acs.accounts.7b00461. PMID 29240396.
  59. ↑ Xu, Zhenhe; Li, Chunxia; Yang, Piaoping; Hou, Zhiyao; Zhang, Cuimiao; Lin, Jun (2009). "Uniform Ln(OH)3 and Ln2O3 (Ln = Eu, Sm) Submicrospindles: Facile Synthesis and Characterization". Crystal Growth & Design. 9 (9): 4127–4135. doi:10.1021/cg9003559.
  60. ↑ Samata, Hiroaki; Hanioka, Masashi; Ozawa, Tadashi C. (2016). "Synthesis and magnetic properties of SmOOH crystals". Journal of Magnetism and Magnetic Materials. 398: 82–85. doi:10.1016/j.jmmm.2015.09.030.
  61. 1 2 Hussein, G. A. M.; Buttrey, D. J.; DeSanto, P.; Abd-Elgaber, A. A.; Roshdy, Heba; Myhoub, Ali Y. Z. (2003). "Formation and characterization of samarium oxide generated from different precursors". Thermochimica Acta. 402 (1–2): 27–36. doi:10.1016/S0040-6031(02)00535-X.
  62. ↑ Vimal, G.; Mani, Kamal P.; Jose, Gijo; Biju, P. R.; Joseph, Cyriac; Unnikrishnan, N. V.; Ittyachen, M. A. (2014). "Growth and spectroscopic properties of samarium oxalate single crystals". Journal of Crystal Growth. 404: 20–25. doi:10.1016/j.jcrysgro.2014.06.041.
  63. ↑ Li, Ming; Wang, Xiaofei; Mao, Chunyan (2024). "The crystal structure of samarium sulfate pentahydrate, Sm2(SO4)3(H2O)5". Zeitschrift für Kristallographie – New Crystal Structures. 239 (2): 201–203. doi:10.1515/ncrs-2023-0480.
  64. ↑ Bouddouch, A.; Amaterz, E.; Taoufyq, A.; Bakiz, B.; Guinneton, F.; Villain, S.; Valmalette, J. C.; Gavarri, J. R.; Benlhachemi, A. (2020). "Photocatalytic and photoluminescent properties of a system based on SmPO4 nanostructure phase". Materials Today: Proceedings. 27: 3139–3144. doi:10.1016/j.matpr.2020.03.803.
  65. ↑ Ogawa, Makoto; Manabe, Kazuo (1993). "Thermal Decomposition of Samarium(III) Acetate Tetrahydrate". Nippon Kagaku Kaishi (5): 600–604. doi:10.1246/nikkashi.1993.600.
  66. ↑ Cotton, Simon A.; Raithby, Paul R. (2017). "Systematics and surprises in lanthanide coordination chemistry". Coordination Chemistry Reviews. 340: 220–231. doi:10.1016/j.ccr.2017.01.011.
  67. ↑ Runschke, Carsten; Meyer, Gerd (1997). "Synthese und Kristallstruktur des monomeren „in-cavity"-Komplexes [SmI3(Dibenzo-18-Krone-6)]". Zeitschrift für anorganische und allgemeine Chemie. 623 (6): 981–984. doi:10.1002/zaac.199762301153.
  68. ↑ Evans, William J.; Gummersheimer, Tammy S.; Ziller, Joseph W. (1995). "Coordination Chemistry of Samarium Diiodide with Ethers Including the Crystal Structure of Tetrahydrofuran-Solvated Samarium Diiodide, SmI2(THF)5". Journal of the American Chemical Society. 117 (35): 8999–9002. doi:10.1021/ja00140a016.
  69. ↑ Yamamoto, Akira; Liu, Xueshi; Arashiba, Kazuya; Konomi, Asuka; Tanaka, Hiromasa; Yoshizawa, Kazunari; Nishibayashi, Yoshiaki; Yoshida, Hisao (2023). "Coordination Structure of Samarium Diiodide in a Tetrahydrofuran–Water Mixture". Inorganic Chemistry. 62 (14): 5348–5356. doi:10.1021/acs.inorgchem.2c03752. PMID 36728764.
  70. ↑ Mironova, Olga A.; Sukhikh, Taisiya S.; Konchenko, Sergey N.; Pushkarevsky, Nikolay A. (2022). "Structural Diversity and Multielectron Reduction Reactivity of Samarium(II) Iodido-β-diketiminate Complexes Dependent on Tetrahydrofuran Content". Inorganic Chemistry. 61 (39): 15484–15498. doi:10.1021/acs.inorgchem.2c02101. PMID 36130049.
  71. ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1248. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
  72. 1 2 3 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1249. doi:10.1016/C2009-0-30414-6. ISBN 978-0-08-037941-8.
  73. ↑ Evans, William J.; Bloom, Ira; Hunter, William E.; Atwood, Jerry L. (1981). "Synthesis and X-ray Crystal Structure of a Soluble Divalent Organosamarium Complex". Journal of the American Chemical Society. 103 (21): 6507–6508. doi:10.1021/ja00411a046.
  74. ↑ Evans, William J.; Hughes, Laura A.; Hanusa, Timothy P. (1984). "Synthesis and Crystallographic Characterization of an Unsolvated, Monomeric Samarium Bis(pentamethylcyclopentadienyl) Organolanthanide Complex, (C5Me5)2Sm". Journal of the American Chemical Society. 106 (15): 4270–4272. doi:10.1021/ja00327a037.
  75. ↑ Evans, William J.; Ulibarri, Tamara A.; Ziller, Joseph W. (1988). "Isolation and X-ray Crystal Structure of the First Dinitrogen Complex of an f-Element Metal, [(C5Me5)2Sm]2N2". Journal of the American Chemical Society. 110 (20): 6877–6879. doi:10.1021/ja00228a043.
  76. ↑ Evans, William J.; Chamberlain, L. R.; Ulibarri, Tamara A.; Ziller, Joseph W. (1988). "Reactivity of trimethylaluminum with (C5Me5)2Sm(THF)2: Synthesis, structure, and reactivity of the samarium methyl complexes (C5Me5)2Sm[(μ-Me)AlMe2(μ-Me)]2Sm(C5Me5)2 and (C5Me5)2SmMe(THF)". Journal of the American Chemical Society. 110 (19): 6423–6432. doi:10.1021/ja00227a023.
  77. 1 2 Szostak, Michal; Fazakerley, Neal J.; Parmar, Dixit; Procter, David J. (2014). "Cross-Coupling Reactions Using Samarium(II) Iodide". Chemical Reviews. 114 (11): 5959–6039. doi:10.1021/cr400685r. PMID 24758360.
  78. ↑ Buschow, K. H. J.; van der Goot, A. S. (1968). "Intermetallic compounds in the system samarium-cobalt". Journal of the Less Common Metals. 14 (3): 323–328. doi:10.1016/0022-5088(68)90037-4.
  79. 1 2 3 Ma, Shuang; Zhang, Hui; Chen, Rujun; Yan, Arun (2022). "Structure and Magnetic Properties of Intermetallic Rare-Earth-Transition-Metal Compounds: A Review". Materials. 15 (1): 201. doi:10.3390/ma15010201. PMC 8745917.
  80. ↑ Kohlmann, Holger; Hansen, Thomas C. (2018). "Magnetic Structure of SmCo5 from 5 K to the Curie Temperature". Inorganic Chemistry. 57 (4): 1702–1704. doi:10.1021/acs.inorgchem.7b02981.
  81. ↑ Song, Xiaoyan; Lu, Nianduan; Seyring, Martin; Rettenmayr, Markus; Xu, Wenwu; Zhang, Zhexu; Zhang, Jiuxing (2009). "Abnormal crystal structure stability of nanocrystalline Sm2Co17 permanent magnet". Applied Physics Letters. 94 (2): 023102. doi:10.1063/1.3040316.
  82. 1 2 Liu, Shiqiang (2019). "Sm–Co high-temperature permanent magnet materials". Chinese Physics B. 28 (1): 017501. doi:10.1088/1674-1056/28/1/017501.{{cite journal}}: CS1 maint: article number as page number (link)
  83. ↑ Wang, Yong; Zhang, Hui; Yang, Jian (2018). "Structure and Phase Transformation in the Giant Magnetostriction Laves-Phase SmFe2". Inorganic Chemistry. 57 (2): 689–694. doi:10.1021/acs.inorgchem.7b02525.
  84. ↑ Borzone, G.; Parodi, N.; Raggio, R.; Ferro, R. (2001). "Thermodynamic investigation of samarium–nickel alloys". Journal of Alloys and Compounds. 317–318: 532–536. doi:10.1016/S0925-8388(00)01382-7.
  85. ↑ Nouri, Kamal; Jemmali, M.; Walha, Siwar (2016). "Structural, atomic Hirschfeld surface, magnetic and magnetocaloric properties of SmNi5 compound". Journal of Alloys and Compounds. 672. doi:10.1016/j.jallcom.2016.02.142.
  86. ↑ Nicolaou, K. C.; Ellery, Shelby P.; Chen, Jason S. (2009). "Samarium Diiodide Mediated Reactions in Total Synthesis". Angewandte Chemie International Edition. 48 (39): 7140–7165. doi:10.1002/anie.200902151. PMC 2771673. PMID 19714695.
  87. ↑ Maity, Sandeepan (2021). "Development in SmI2 Catalyzed Reactions". European Journal of Organic Chemistry. 2021 (37): 5312–5319. doi:10.1002/ejoc.202100962.
  88. ↑ Otsuka, Kiyoshi; Jinno, Kiyotaka; Morikawa, Akira (1986). "Active and selective catalysts for the synthesis of C2H4 and C2H6 via oxidative coupling of methane". Journal of Catalysis. 100 (2): 353–359. doi:10.1016/0021-9517(86)90102-8.
  89. ↑ Seshadri, M.; Rao, K. V.; Rao, J. L.; Ratnakaram, Y. C. (2009). "Spectroscopic and laser properties of Sm3+ doped different phosphate glasses". Journal of Alloys and Compounds. 476 (1–2): 263–270. doi:10.1016/j.jallcom.2008.09.033.
  90. ↑ Ratnam, B. V.; Jayasimhadri, M.; Jang, Kiwan (2014). "Luminescent properties of orange emissive Sm3+-activated thermally stable phosphate phosphor for optical devices". Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 132: 563–567. doi:10.1016/j.saa.2014.04.189. PMID 24892535.
  91. ↑ Dzero, Maxim; Xia, Jing; Galitski, Victor; Coleman, Piers (2016). "Topological Kondo Insulators". Annual Review of Condensed Matter Physics. 7: 249–280. doi:10.1146/annurev-conmatphys-031214-014749.
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