Magnetoresistance and thermoelectric power of La-chalcogenides (La2.989S4, La2.985Se4, Ce3S4)

Kim, D.C.; Kim, J.S.; McIntosch, G.C.; Park, Y.W.; Nahm, Kyun; Pelzl, J.

doi:10.1016/s0921-4534(01)00787-0

Cited by 7 publications

(4 citation statements)

References 13 publications

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“…Both binary lanthanum and antimony chalcogenides are under investigation for their potential use as thermoelectric materials. , This includes not only the telluride Sb 2 Te 3 , , which is also a part of the record-breaking Bi 2 Te 3 /Sb 2 Te 3 thin film device, but also the sulfide Sb 2 S 3 . The same is true for the lanthanum sulfides, − selenides, and tellurides. − La 2 S 3 in the cubic γ modification (defect La 3 - δ S 4 , δ = 0.33, Th 3 P 4 type) was reported to reach a ZT value of 0.5 at 1000 K . Very little comprehensive information about the Ln 2 Q 3 /Sb 2 Q 3 system (Ln = lanthanoid, Q = S, Se, Te) could be found in the literature; aside from vague reports on La 6 Sb 8 S 21 and La 3 Sb 3 S 10 , and the isostructural Ce compounds, the structures of Eu 3 Sb 4 S 9 17 and Pr 8 Sb 2 S 15 18 were solved.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Structure, and Electronic Structure of the Ternary Sulfide La₇Sb₉S₂₄

Assoud

Kleinke

2006

Chem. Mater.

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A ternary sulfide exists on the quasi-binary section La 2 S 3 -Sb 2 S 3 , La 7+δ Sb 9-δ S 24 . This material exhibits a small but significant phase range with at least -0.296(4) e δ e 0.134(6). La 7+δ Sb 9-δ S 24 forms a new structure type, space group P2 1 /c, with a ) 8.7115(9) Å, b ) 14.3450(15) Å, c ) 15.2657(16) Å, β ) 90.105(2)°(Z ) 2) for δ ) 0.13. This structure contains chains of severely distorted SbS 5 square antiprisms, interconnected by eight-and nine-coordination La atoms. One position is mixed-occupied by La and Sb, with the La content ranging at least from 57% to 35%. La 7 Sb 9 S 24 is a blackish material with a computed gap >1.5 eV.

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Section: Introductionmentioning

confidence: 99%

Synthesis, Structure, and Electronic Structure of the Ternary Sulfide La₇Sb₉S₂₄

Assoud

Kleinke

2006

Chem. Mater.

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“…Since that time, several groups have investigated rare-earth sulfides [31][32][33][34][35][36][37] and have confirmed that they have a relatively high ZT (about 0.7-0.8 at 1200 K for RS 1.48 , the best composition according to refs. 30 and 35), but apparently lower than for lanthanum tellurides that have been recently thoroughly investigated by Snyder's group [39][40][41][42].…”

Section: Introductionmentioning

confidence: 99%

“…Actually, from the experimental data, it is difficult to understand if the tellurides have really significantly better TE properties than the sulfides or if this is due to a better optimization of the doping of the tellurides. Concerning the selenides, there are too few studies concerning the TE properties [7,26,37,38] and they don't permit to verify if they have TE properties comparable to the sulfides or the tellurides. Because of the problem of the low abundance of tellurium and even of selenium, it is obvious that if one could obtain a ZT higher than 1 in the rare-earth sulfides, this would have a large impact in the thermoelectric field.…”

Section: Introductionmentioning

confidence: 99%

Physical properties of the thermoelectric cubic lanthanum chalcogenides La3−yX4(X= S, Se, Te) from first principles

2013

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We report ab-initio calculations of the stability, lattice dynamics, electronic and thermoelectric properties of cubic La 3-y X 4 (X=S,Se,Te) materials in view of analyzing their potential for thermoelectric applications. The lanthanum motions are strongly coupled to the tellurium motions in the telluride, whereas the motions of both types of atoms are decoupled in the sulfides. Nevertheless, this has no impact on their thermal properties because experimentally all compounds have low thermal conductivity. We believe that this is due to Umklapp scattering of the acoustical modes, notably by the low energy optical modes at about 7-8 meV found in all three chalcogenides, as in cage compounds such as skutterudites or clathrates, even though there are no cages in the cubic Th 3 P 4 structure. We find that the energy bandgap increases from the telluride to the sulfide in good agreement with the experiments. However, due to their similar band structure, we find that all three compounds have almost identical thermoelectric properties. Our results agree qualitatively with the experiments, especially in the case of the telluride for which a great amount of data exists. All our results indicate that the sulfides have strong potential for thermoelectricity and could replace the tellurides if the charge carrier concentration is optimized. Finally, we predict also a larger maximum ZT for the p-type doped materials than for the n-type doped ones, even though compounds with p-doping have still to be synthesized.Thus our results indicate the possibility to make high temperature performing thermo-generators based only on La 3 X 4 compounds.PACS numbers: 63.20.dk,71.15.Nc, 72.15.Jf, 72.20.Pa 1

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“…Quaternary metal chalcogenides that contain an alkali metal or alkaline‐earth metal together with a lanthanide metal and a transition or main‐group metal show interesting structural chemistry and a wide range of physical properties, for example magnetism, optical properties, thermoelectricity, and charge density waves 1–4. Examples of these compounds include the one‐dimensional structures of Ba 3 Ln InS 6 ( Ln = Pr, Sm, Gd, Yb)5 and Ba 2 Ln GaS 5 ( Ln = Pr, Nd),5 the two‐dimensional structures of KCuCe 2 Se 6 6 and KCuZrS 3 ,7 and the three‐dimensional structures of CsCu 3 Ln 2 S 5 ( Ln = Dy, Er)8 and BaAgErS 3 9…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Cytotoxicity of the Proposed Structure of Piperazirum, Its Stereoisomers and Analogues

et al. 2013

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Piperazirum, a new biologically active alkaloid isolated from Arum palaestinum Bioss, is described, starting from commercially available α‐amino acids. Two synthetic strategies were developed for the synthesis of the enantiomeric pair of compounds corresponding to the proposed structure of piperazirum. The first strategy was used in the synthesis of stereoisomers, and the second one was used in generating the analogues. The compounds synthesized were screened against different cell lines to evaluate their cytotoxicity profiles.

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Magnetoresistance and thermoelectric power of La-chalcogenides (La2.989S4, La2.985Se4, Ce3S4)

Cited by 7 publications

References 13 publications

Synthesis, Structure, and Electronic Structure of the Ternary Sulfide La₇Sb₉S₂₄

Synthesis, Structure, and Electronic Structure of the Ternary Sulfide La₇Sb₉S₂₄

Physical properties of the thermoelectric cubic lanthanum chalcogenides La3−yX4(X= S, Se, Te) from first principles

Synthesis and Cytotoxicity of the Proposed Structure of Piperazirum, Its Stereoisomers and Analogues

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Magnetoresistance and thermoelectric power of La-chalcogenides (La2.989S4, La2.985Se4, Ce3S4)

Cited by 7 publications

References 13 publications

Synthesis, Structure, and Electronic Structure of the Ternary Sulfide La7Sb9S24

Synthesis, Structure, and Electronic Structure of the Ternary Sulfide La7Sb9S24

Physical properties of the thermoelectric cubic lanthanum chalcogenides La3−yX4(X= S, Se, Te) from first principles

Synthesis and Cytotoxicity of the Proposed Structure of Piperazirum, Its Stereoisomers and Analogues

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Synthesis, Structure, and Electronic Structure of the Ternary Sulfide La₇Sb₉S₂₄

Synthesis, Structure, and Electronic Structure of the Ternary Sulfide La₇Sb₉S₂₄