New Compounds of the ThCr2Si2-Type and the Electronic Structure of CaM2Ge2 (M: Mn–Zn)

Investigation of thermophysical, electronic and lattice dynamic properties for CaX2Si2 (X=Ni,Zn,Cu,Ag,Au) via first-principles calculations

“…The calculated lattice constants and c/a ratio of CaNi 2 Si 2 in this work are well represented the experimental data [15,17], however the c/a ratio of CaZn 2 Si 2 shows a small difference about 4.9% between the calculated result and experimental data [16]. Most of the optimized z values in series of CaX 2 Si 2 compounds are coincident with the experimental observation, except that of CaAu 2 Si 2 with 6% deviation.…”

“…Besides the aforementioned compounds, more novel materials like CaCu 2 Si 2 [13], CaAu 2 Si 2 [14], CaNi 2 Si 2 [15] and CaZn 2 Si 2 [16] are recently synthesized and characterized with ThCr 2 Si 2 -type structure. CaNi 2 Si 2 has been selected as the representative to investigate the electron-density distribution by using X-ray diffraction and first-principles calculations [17].…”

The new series of RZnGe compounds (R=rare earth element) with the YPtAs structure type

“…For all the other systems, no information on the ternary phase diagram is available; however, the existence and the crystal structure of some ternary compounds have been reported. In particular, the following phases are known: EuZnGe and YbZnGe (ZrBeSi and CeCu 2 type, respectively) [4,5]; YbZn 2 Ge 2 (BaAl 4 type) [6]; EuZn 2 Ge 2 , reported with both the CaBe 2 Ge 2 structure [7] and the ThCr 2 Si 2 type [8]; R 2 Zn 6 Ge 3 with R ¼ La, Ce, Pr, Sm, Gd (Ce 2 Zn 6 Ge 3 type) [9]; R 4 Zn 5 Ge 6 with R ¼ Gd, Tm and Lu [10] and Tb 4 Zn 5 Ge 6 [11] (Gd 4 Zn 5 Ge 6 type), R 4 Zn 8 Ge w10 with R ¼ Ce, Nd, Gd (Ce 4 Zn 8 Ge 11Àx type) [12]; R 2 Zn 15 Ge 2 with R ¼ Ce, Nd (Th 2 Zn 17 type) [13,14]; RZn 1.5 Ge 0.5 (R ¼ La-Sm), belonging to the AlB 2 type (or some AlB 2 derivative) [15], La 5 ZnGe 3 (La 5 CrGe 3 type) [16]. More recently, the crystal structure of the novel ytterbium zinc germanide (Yb 2 Zn 3 Ge 3.1 ) [17] and of the Re 2 Zn 3 Ge 6 compounds (Re ¼ La, Ce, Pr, Nd [18]) have been also elucidated.…”

Synthesis and properties of CaCd2Sb2 and EuCd2Sb2

“…The compounds with a nominal composition of AM 2 X 2 (A is alkaline-earth or rare-earth element, M is a transition-metal or a main group element, and X comes from group 15, 14, or more rarely 13) favorably crystallize in ThCr 2 Si 2 type structure (I4/mmm) [11,12],…”

“…Recently, in attempts to develop TE materials, novel antimonide analogues of Zintl phases, which are stable in air, were investigated, i.e., Yb 14 MnSb 11 [3], bZn 4 Sb 3 [4], filled skutterudite [5], Mg 3 Sb 2 [6], Ca x Yb 1Àx Zn 2 Sb 2 [7], YbZn 2Àx Mn x Sb 2 [8], EuZn 2 Sb 2 [9], YbCd 2Àx Zn x Sb 2 [10] etc. Among these materials, Ca x Yb 1Àx Zn 2 Sb 2 [7], YbZn 2Àx Mn x Sb 2 [8], EuZn 2 Sb 2 [9] and YbCd 2Àx Zn x Sb 2 [10] showed promising ZT values.The compounds with a nominal composition of AM 2 X 2 (A is alkaline-earth or rare-earth element, M is a transition-metal or a main group element, and X comes from group 15, 14, or more rarely 13) favorably crystallize in ThCr 2 Si 2 type structure (I4/mmm) [11,12], …”