Structure and Properties of Dimorphic CePdZn

Abstract

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 2 ences between α-and β-CePdZn regarding the total energy and the Ce(4f)-Pd(4d) hybridization. Running title: Structure and Properties of Dimorphic CePdZn

Dimorphism in the REPdZn series

“…In analogy to our previous work on the two modifications of CePdZn [9] we observed temperature driven dimorphism also for YPdZn, PrPdZn, ErPdZn, TmPdZn, and LuPdZn. The cell volumes per formula unit of the REPdZn intermetallics as a function of the rare earth element are presented in Fig.…”

“…Analyses of the b-YPdZn, LaPdZn, and b-TmPdZn data sets showed primitive orthorhombic lattices and the systematic extinctions were compatible with space group Pnma in agreement with the previously reported high-temperature phase b-CePdZn [9]. The atomic positions of b-CePdZn were taken as staring parameters and the three structures were refined with anisotropic atomic displacement parameters for all atoms using SHELXLe97 (full-matrix least-squares on F 2 ) [25,26].…”

“…The atomic positions of b-CePdZn were taken as staring parameters and the three structures were refined with anisotropic atomic displacement parameters for all atoms using SHELXLe97 (full-matrix least-squares on F 2 ) [25,26]. The remaining data sets showed hexagonal lattices and no further systematic extinctions, leading to the non-centrosymmetric space group P 62m (isotypism with ZrNiAl type a-CePdZn [9]). These structures were refined with the setting of a-CePdZn.…”

“…So far only powder X-ray diffraction data had been published for ZrNiAl type REPdZn (RE ¼ Ce, Pr, Sm, Gd, Dy, Er) [1] and single crystal data for LT-and HT-CePdZn [9], EuPdZn [7], and YbPdZn [3]. Herein we report on the synthesis, the structural characterization, and the thermal behavior of the remaining compounds of the REPdZn series.…”

“…The structurally most interesting compound is dimorphic CePdZn [1,9], which adopts the ZrNiAl structure at low temperatures (LT) and transforms to the TiNiSi type at high temperatures (HT). Such temperature driven phase transitions have also been observed for the stannides REPtSn (RE ¼ Y, Gd, Tb) [14] and TmAgSn [15], while CePtSn [16] and CePdSn [17] show these structural changes upon high-pressure high-temperature treatment.…”