Structure and Properties of Dimorphic CePdZn

Rainer Poettgen (1) , Wilfried Hermes , Dirk Johrendt , Helen Müller , Ratikanta Mishra

1 Inst. f. Anorgan. u. Analyt. Chemie

Two modifications of CePdZn have been synthesized and structurally characterized. The high-temperature (HT) Β-CePdZn modification forms upon quenching from the melt. The Β-CePdZn structure adopts the orthorhombic TiNiSi type and transforms to the low-temperature (LT) Α-CePdZn modification (ZrNiAl type) upon annealing at 1080 K. Both modifications have been studied by X-ray powder and single crystal data: P6–2m, a = 740.4(1), c = 402.18(5) pm, wR2 = 0.0427, 237 F2 values and 14 variables for Α-CePdZn and Pnma, a = 707.2(2), b = 441.4(2), c = 806.3(3) pm, wR2 = 0.0827, 469 F2 values and 20 variables for Β-CePdZn. The palladium and zinc atoms build up three-dimensional [PdZn] networks in both modifications which leave channels for the cerium atoms. Both modifications show stable trivalent cerium. β-CePdZn orders antiferromag-netically at 3.2(1) K while no magnetic ordering has been observed for α-CePdZn down to 2 K. The course of the magnetic data points to stronger Ce(4f)–Pd(4d) hybridization in a-CePdZn. Electronic structure calculations reveal only small differences between a- and b-CePdZn regarding the total energy and the Ce(4f)–Pd(4d) hybridization.

Mots clés: Physical Sciences

Rainer Poettgen, Wilfried Hermes, Dirk Johrendt, Helen Müller, Ratikanta Mishra. Structure and Properties of Dimorphic CePdZn. Journal of Inorganic and General Chemistry / Zeitschrift für anorganische und allgemeine Chemie, 2009, 635 (4-5), pp.660. ⟨10.1002/zaac.200900054⟩. ⟨hal-00482073⟩