Magnetic properties and structure of LaNi3/4Mn1/4O3

We report here the structure and magnetic properties of LaNi3/4Mn1/4O3. X-ray diffraction and transmission electron microscopy experiments demonstrate that this sample is a single perovskite phase and not a biphasic system as was thought in the past. The thermal evolution of the ac magnetic susceptibility shows two large magnetic anomalies at 45 and 262 K. Isothermal magnetization measurements indicate the presence of a very low ferromagnetic component below 262 K. The neutron diffraction experiments, instead, do not detect a magnetic contribution for this sample in the whole temperature range measured. The complex magnetic behaviour can be explained as a glassy ferromagnetic state, a phase with properties typical of both systems: ferromagnets and spin-glasses.