Crystal chemistry and thermoelectric properties of Gd₂Te₃

Abstract

Gd2Te3, M

Cs2Gd6N2Te7: The first quaternary nitride telluride of the lanthanides

“…The distances d(Gd 3+ -N 3− ) amount to 217-244 pm and d(Gd 3+ -Te 2− ) to 305-327 pm, respectively, as shown in Table 3. These values are in good agreement with the Gd-N distances in the crystal structures of Gd 3 NS 3 (220-232 pm) [2] or Gd 2 NCl 3 (226-228 pm) [14] and Gd 3 NCl 6 (224-231 pm) [15] as well as with the Gd-Te distances in gadolinium sesquitelluride Gd 2 Te 3 [16] with U 2 S 3 -type structure (311-323 pm, C.N. = 7) or Cs 3 Gd 7 Te 12 (304-322 pm, C.N.…”

“…A comparison of the Madelung Part of the Lattice Energy (MAPLE according to Hoppe [21]) for Cs 2 Gd 6 N 2 Te 7 with the sum of the formally underlying three binary components Cs 2 Te [18], Gd 2 Te 3 (U type) [16], and GdN (NaCl type) [22] also gives a convincing result. By taking 1× 434 + 2× 2666 + 2× 2092 kJ/mol a value of 9950 kJ/mol for the sum (MAPLE(Cs 2 Te) + 2× MAPLE(Gd 2 Te 3 ) + 2× MAPLE(GdN)) emerges, which only deviates by −0.7% from MAPLE of Cs 2 Gd 6 N 2 Te 7 (10016 kJ/mol) itself.…”

Syntheses and Crystal Structures of CsCuNd2Se4 and CsCuGd2Te4: Two Non‐Isotypical Cesium Copper Lanthanide Chalcogenides with {}^1_\infty{[CuCh3]5–} Chains of Vertex‐Shared [CuCh4]7– Tetrahedra

“…The distances d (Nd–Se) that range between 289 and 304 pm in CsCuNd 2 Se 4 , are in fair agreement with those of Nd 2 Se 3 ( d (Nd–Se) = 297–317 pm, CN(Nd 3+ ) = 8) 20 and CuNdSe 2 ( d (Nd–Se) = 293–316 pm, CN(Nd 3+ ) = 6) 21. The distances between Gd 3+ and Te 2– in CsCuGd 2 Te 4 covering an interval from 300 to 318 pm are consistent for example with those in Gd 2 Te 3 ( d (Gd–Te) = 311–367 pm, CN(Gd 3+ ) = 7 and 8) 22 and in Cs 3 Cu 5 Gd 4 Te 10 ( d (Gd–Te) = 297–327 pm, CN(Gd 3+ ) = 6) 11. The short Cu + ···Gd 3+ separations of only 284, 305 and 340 pm in the CsCuGd 2 Te 4 structure resulting from the face‐connection of tetrahedral and octahedral units are also found in the isotypical compound CsCuY 2 Te 4 (with 281, 301 and 334 pm) and in other quaternary cesium copper tellurides (e.g.…”

Caesium Gadolinium Tetratelluride

“…Within the [GdTe4]g-layers, the Gd cations are in an ideal square-antiprismatic environment of Te with a GdmTe distance of 3.2132 (4).4,. This distance is only slightly longer than the Gd--Te distances in the binary telluride Gd2Te3 (<Gd--Te> = 3.126 and 3.189 A for the two crystaUographically independent Gd atoms; Swinnea, Steinfink & Danielson, 1987). The Cs CsGdTe4 <Cs2mTe> = 3.925 A,; B6ttcher & Kretschmann, 1985) or Cs3Te22 (<CsmTe> = 3.892 ~,; Sheldrick & Wachhold, 1995 (Selte & Kjekshus, 1964).…”