Magnetic properties of some light rare−earth compounds with CsCl structure

Abstract

Neutron−diffraction studies were performed on the compounds PrZn, NdZn, NdMg, and NdAg. The lattice constants were determined at 300 and 4.2 K. For all compounds the CsCl structure was confirmed at room temperature. The compound PrZn was found to be subject to a tetragonal distortion at 4.2 K. A very small tetragonal distortion exists probably also in NdZn and NdMg at 4.2 K. the magnetic moment of the rare−earth component and the magnetic structure type was determined. All compounds are antiferromagnetic at 4.2 K, PrZn and NdMg with the 〈0,0,π〉 structure, NdAg with the 〈π,π,0〉 structure. In view of the generally accepted explanation of the magnetic properties of CsCl−type intermetallics in terms of the RKKY model these findings for PrZn and NdMg are remarkable and form a discrepancy with the ferromagnetic nature of the heavy rare−earth counterparts of these compounds.