Structure and magnetic properties of the REAuBi2 (RE=La-Nd, Sm) phases

We present the crystal structures and basic magnetic properties of the REAuBi2 (RE= La-Nd, Sm) compounds. This isostructural family crystallizes in the tetragonal P4/nmm (no. 129) HfCuSi2-type, as determined by single crystal X-ray diffraction. Three distinct substructures are present: an RE layer, a tetrahedral AuBi layer, and a Bi square net layer. Electronic structure calculations indicate that these compounds display bands which cross the Fermi level, derived from both the Bi square net and the covalent AuBi layer. The small size of LaAuBi2 crystals precluded detailed physical property measurements, whereas large single crystals could be grown for all other phases investigated here. Single crystal measurements of CeAuBi2, PrAuBi2, and NdAuBi2 show overall antiferromagnetic ordering and decreasing magnetic anisotropy with decreasing rare earth size. SmAuBi2 also shows signatures of magnetic ordering. (C) 2015 Elsevier Inc. All rights reserved.