CRYSTALLINE ELECTRIC-FIELD AND HIGH-FIELD MAGNETIZATION IN ERNI5 SINGLE-CRYSTAL

High field magnetization measurements up to 380 kOe along the three sy mmetry axes of a single-crystalline sample of hexagonal ErNi5, especia lly the curves along [100] and [120] show us for the first time the st rong field induced anisotropy between the two axes in the basal plane. A quantitative analysis of this experiment together with the other da ta such as paramagnetic susceptibility, specific heat and inelastic ne utron scattering allowed us to determine unambiguously the crystalline electric field (CEF) parameters and the paramagnetic exchange coeffic ient. This leads to a better understanding of the CEF anisotropy in th e basal plane. The Er3+ CEF interactions are compared with those found in other RNi5 compounds.