Change in Magnetization of the Fe/Pb/Zr/BaTiO₃ System Driven by Time of Mechanochemical Activation and Thermal Treatment

Abstract

Mixtures of high purity powders of 50 mass % Fe, 4 mass % Pb, 3 mass % Zr and 43 mass % BaTiO3 were activated in a rotary ball mill for durations ranging from 30 min to 300 min. Samples were then pressed and sintered in the air atmosphere for 2 hours at 1200 °C. It was observed that the pressing alone, i.e. without sintering, led to a decrease of magnetization in all of the samples, with the process of sintering decreasing it further, with the most dramatic drop of 90.11 % belonging to the sample activated for 150 min. Samples activated for 90 min, 180 min and 300 min were subjected to subsequent cycles of heating to Curie temperature of 345.26 °C, then cooling to 25 °C, in the applied magnetic field of 20 kA m-1, where an increase of magnetization in all of the samples was observed, with the biggest increase in magnetization of 198.56 % observed for the sample activated for 300 min.