Magnetic Properties and Structure of Materials Obtained from Solid-State Reaction Process between Iron and Boron Nitride Induced by Mechanical Milling

Resumo

The powder mixture of the iron and hexagonal boron nitride subjected to mechanical milling using the high energy ball mill to obtain hard magnetic material has been investigated by XRD, SEM, DSC, and VSM methods. The components ratio in the mixture has been selected as 1 : 1. The initially soft magnetic powder shows hard magnetic properties already after 7 hours of mechanical milling. Increasing time of milling from 7 to 60 h leads to increase the coercivity of the powder mixture. The following annealing changes the phase composition and magnetic properties of the mechanical activated powder. The maximum magnetic properties values have been obtained after annealing at 500°C within 5 h in the nitrogen atmosphere: saturation magnetization σ_S = 70 emu/g, coercivity = 42 kA/m (525 Oe).