TY - JOUR
T1 - Tl 2AXTe 4 (A = Cd, Hg, Mn; X = Ge, Sn)
T2 - Crystal structure, electronic structure, and thermoelectric properties
AU - McGuire, Michael A.
AU - Scheidemantel, Thomas J.
AU - Badding, John V.
AU - DiSalvo, Francis J.
PY - 2005/11/29
Y1 - 2005/11/29
N2 - The six new compounds Tl 2CdGeTe 4, Tl 2CdSnTe 4, Tl 2HgGeTe 4, Tl 2HgSnTe 4, Tl 2MnGeTe 4, and Tl 2-MnSnTe 4 have been synthesized. All six compounds are isostructural and crystallize in the tetragonal space group I-42m with a ≈ 8.3 Å and c ≈ 7.1 Å. The structure is composed of chains of composition [AXTe 4] 2- separated by Tl 1+ ions, an ordered superstructure of the TlSe structure type. In addition to their syntheses and crystal structures, we report the calculated electronic structures of these six compounds and of the related compounds KInTe 2 and TlInTe 2. We measured the thermoelectric properties (electrical resistivity, thermopower, and thermal conductivity) of Tl 2CdGeTe 4, Tl 2CdSnTe 4, Tl 2HgGeTe 4, and Tl 2-HgSnTe 4. These compounds are semiconductors with very low thermal conductivities and moderately high thermopowers. However, as currently prepared they have resistivities that are too high for thermoelectric applications. Magnetic susceptibility and resistivity measurements show Tl 2MnGeTe 4 and Tl 2MnSnTe 4 to be Mott insulators, in agreement with spin-polarized band structure calculations.
AB - The six new compounds Tl 2CdGeTe 4, Tl 2CdSnTe 4, Tl 2HgGeTe 4, Tl 2HgSnTe 4, Tl 2MnGeTe 4, and Tl 2-MnSnTe 4 have been synthesized. All six compounds are isostructural and crystallize in the tetragonal space group I-42m with a ≈ 8.3 Å and c ≈ 7.1 Å. The structure is composed of chains of composition [AXTe 4] 2- separated by Tl 1+ ions, an ordered superstructure of the TlSe structure type. In addition to their syntheses and crystal structures, we report the calculated electronic structures of these six compounds and of the related compounds KInTe 2 and TlInTe 2. We measured the thermoelectric properties (electrical resistivity, thermopower, and thermal conductivity) of Tl 2CdGeTe 4, Tl 2CdSnTe 4, Tl 2HgGeTe 4, and Tl 2-HgSnTe 4. These compounds are semiconductors with very low thermal conductivities and moderately high thermopowers. However, as currently prepared they have resistivities that are too high for thermoelectric applications. Magnetic susceptibility and resistivity measurements show Tl 2MnGeTe 4 and Tl 2MnSnTe 4 to be Mott insulators, in agreement with spin-polarized band structure calculations.
UR - http://www.scopus.com/inward/record.url?scp=28944435579&partnerID=8YFLogxK
U2 - 10.1021/cm0518067
DO - 10.1021/cm0518067
M3 - Article
AN - SCOPUS:28944435579
SN - 0897-4756
VL - 17
SP - 6186
EP - 6191
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 24
ER -