High field induced first order magnetization process in NdCo 5 single crystal

Abstract

Low temperature high field magnetization measurements up to 380 kOe along the three symmetry axes of a single-crystalline sample of hexagonal NdCo 5 are presented. Along the hard [001] direction a very sharp First Order Magnetization Process (FOMP) is observed at 340 kOe. A self consistent quantitative analysis, using a phenomenological approach for the Co magnetism and a perturbing Hamiltonian for the Nd magnetism allowed us to give a satisfactory account for these experiments and of the thermal dependence of the direction of the spontaneous magnetization. The FOMP arises from the field effect on the crystal field splitting acting on Nd 3+ ions together with the Nd-Co exchange interaction and the Co anisotropy which favours the [001] axis. A range of crystal field and Nd-Co exchange parameters is proposed.