A switch from homogeneous mixed-valent to trivalent cerium in the solid solutions CeNi_1–<i>x</i>Pd_<i>x</i>Zn

Abstract CeNiZn and α -CePdZn (both ZrNiAl type, hexagonal space group P 6‾2 m ) form a complete range of solid solutions CeNi 1– x Pd x Zn. Samples were synthesized with steps of x = 0.1 or 0.05 from the pure elements by induction-melting. The structure of CeNi 0.59(1) Pd 0.41 Zn was refined from single crystal X-ray diffractometer data: a = 727.61(8), c = 396.75(4) pm, w R 2 = 0.0301, 297 F 2 values and 17 variables. Both the 1 a and 2 d transition metal sites show Ni/Pd mixing. The cell volume decreases from α -CePdZn to CeNiZn in a discontinuous manner. This is directly related to a change in the cerium magnetic ground state. The properties change from Curie-Weiss paramagnetic α -CePdZn to homogeneous mixed valence in CeNiZn. The magnetic susceptibility data of the intermediate-valence representatives could be fitted with the Sales-Wohlleben interconfiguration-fluctuation model.