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Structure and Properties of Dimorphic CePdZn
Author(s) -
Hermes Wilfried,
Mishra Ratikanta,
Müller Helen,
Johrendt Dirk,
Pöttgen Rainer
Publication year - 2009
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200900054
Subject(s) - orthorhombic crystal system , cerium , crystallography , crystal structure , annealing (glass) , single crystal , materials science , chemistry , metallurgy
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: P $/bar{6}$ 2 m , a = 740.4(1), c = 402.18(5) pm, wR 2 = 0.0427, 237 F 2 values and 14 variables for α‐CePdZn and Pnma , a = 707.2(2), b = 441.4(2), c = 806.3(3) pm, wR 2 = 0.0827, 469 F 2 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 antiferromagnetically 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(4 f )–Pd(4 d ) hybridization in α‐CePdZn. Electronic structure calculations reveal only small differences between α‐ and β‐CePdZn regarding the total energy and the Ce(4f)–Pd(4d) hybridization.