The microstructure and magnetic properties of FeCo alloys with different OH/(Co~(2+), Fe~(2+)) ratio and annealing temperature

摘要

The OH/(Co~(2+), Fe~(2+)) ratio and annealing temperature (T_a) have a great influence on the microstructure and magnetic properties of FeCo alloys. In this work, the OH/(Co~(2+), Fe~(2+)) ratio was first changed from 10∶1 to 30∶1. When the OH/ (Co~(2+), Fe~(2+)) ratio was 20∶1, pure FeCo powder samples were obtained. After annealing at 400 °C, the saturation magnetization (M_s), remnant magnetization (M_r), and coercivity (H_c) were 155 emu/g, 15 emu/g, and 210 Oe, respectively. Then the prepared FeCo samples were annealed in the range of 300 °C-600 °C for 5 h. With the increasing of T_a, the better magnetic properties of FeCo powders were observed. When the T_a was 600 °C, the M_s, M_r, and H_c were 202 emu/g, 12 emu/g, and 87 Oe, respectively. When the OH/(Co~(2+), Fe~(2+))-= 20∶1 and T_a was 400 °C, the real part of complex permittivity was between 8.2 and 9.5, and the corresponding imaginary part was between - 0.3 and 1.3. Furthermore, the maximum reflection loss (RL) value of FeCo powders (20-30 nm) was - 35.49 dB which showed great potential in corresponding industrial applications.