Magnetic instabilities in [formula omitted] studied by NMR

Abstract

The field dependence of 59Co NMR in ferrimagnetic Er 1 - x Y x Co 3 was measured up to 8 T at 4.2 K. For pure ErCo 3 in fields perpendicular to the c axis the resonance frequencies change discontinuously between 2 and 3 T due to a field induced metamagnetic transition. The transition is characterized by rotations of Er and Co magnetic moments away from the easy c-axis. The angles between the Co moments and the c axis at x = 0.1 are obtained. The easy axis is found to be along the c axis for x = 0 and 0.1, and inclined from the c axis for x = 0.3 and 0.5.