Magnetic instabilities in Er1-xYxCo3 pseudo-binary compounds (x=0.1, 0.3, and 0.5)

For the ferrimagnetic compound ErCo3 (T-C = 401 K), a temperature-induced magnetic transition in the Co-sublattices near 100K was reported previously. The Co-moments of two of the three non-equivalent Co-sites increase discontinuously upon cooling below this transition temperature. Here, we report on the investigation of this metamagnetic transition when the molecular field is reduced, partly substituting Er by Y. Neutron-diffraction experiments on Er1-xYxCo3 compounds reveal that this temperature-induced magnetic transition vanishes for x >= 0.3. As new phenomenon, a spin-reorientation out of the c-axis is observednear 40K when Er is partly replaced by Y. Both phenomena are studied by neutron and NMR experiments. (C) 2004 Elsevier B.V. All rights reserved.