CeNi1-xSb1+yBi1-y Phases with ZrCuSiAs-type and CeNi1.26Sb2 with CaBe2Ge2-type Structure

Abstract

Block- and platelet-shaped single crystals of several CeNi1-xSb1+yBi1-y phases with ZrCuSiAstype structure (space group P4=nmm) were grown from a CeNiSb precursor in bismuth fluxes. The structures of CeNiSb1.19Bi0.81, CeNi0.80Sb1.16Bi0.84 and CeNi0.75Sb1.74Bi0.26 were refined from single-crystal X-ray diffractometer data. The 2b nickel site can be fully or partially occupied, and the bismuth square nets show solid solutions with antimony. CaBe2Ge2-type CeNi2-xSb2 crystals occur as by-products of the crystal growth experiments. The structure of a CeNi1.26Sb2 crystal has been refined. The small difference of the compositions hamper phase analytical studies by powder X-ray diffraction. A polycrystalline CeNiSbBi sample showed Curie-Weiss behavior with an experimental magnetic moment of 2.56(1) μB per Ce atom, indicating purely trivalent cerium. No magnetic ordering is detected down to 2:5 K. A 121Sb Mössbauer spectrum showed an isomer shift of δ = -8.06(6)mms-1, substantiating the antimonide character.