MAGNETIC-PROPERTIES AND MAGNETIC-STRUCTURES OF HO1-XYXNI COMPOUNDS

The magnetic properties of orthorhombic Ho1-xYxNi compounds have been studied from resistivity, magnetization and neutron diffraction experiments. The Curie temperatures decrease linearly from 37.5 K in HoNi to 4 K for Ho0.2Y0.8Ni, while Ho0.1Y0.9Ni and YNi do not present any magnetic long-range order. Below T-C the compounds show a non-collinear magnetic structure belonging to a single irreducible representation, which evolves at lower temperatures towards another non-collinear structure described by the mixture of two irreducible representations. The appearance of both magnetic arrangements is discussed, comparing these structures with those of other rare earth nickel compounds and taking into account both crystalline electric field and exchange interactions.