Magnetism in RENiAl compounds

Abstract

Results of magnetic, resistivity and specific heat measurements of RENiAl compounds are presented. Except for CeNiAl, all the compounds with the unfilled f-shell rare earths exhibit magnetic ordering at low temperatures. In the majority of cases, we observe one or two additional magnetic phase transitions below the ordering temperature. In RENiAl antiferromagnets, metamagnetic transitions are observed in moderate magnetic fields. Magnetization measurements performed on oriented powders reveal a strong magnetocrystalline anisotropy (except for GdNiAl and CeNiAl) which originates in crystal field interaction. The energy spectra of the RE 4f states were obtained from the analysis of the Schottky anomalies found in the specific heat data. This analysis also revealed indications of strong magnetic correlations in the paramagnetic state.