Magnetic Properties of Sm-Fe-Co-Ga-N Compounds and Bonded Magnets Made from Them

Abstract

An experiment was carried out to investigate the magnetic and physical properties of Sm-Fe-Ga-N and Sm-FeCo-Ga-N compounds. These compounds were prepared by nitrogenation of Sm₂Fe_17-xGa_x and Sm₂ (Fe_0.9Co_0.1)_16.7 Ga_0.3 powders (about 30μm) in high-purity nitrogen gas at pressures of 4.9 MPa, and temperatures of 475-600°C for 1-4 h.It was found that the value of the anisotropy field (H_A) in Sm₂Fe_17-xGa_xN_y compounds increased with increasing Ga concentration (up to x=0.3), while the saturation magnetization (σ_s) decreased. The values of H_A and σ_s in nitride of Sm₂Fe1_6.7Ga_0.3 were 9.95 MA/m and 188.5 Wb· m/kg, respectively.The magnetic and physical properties of an anisotropic Sm₂Fe_16.7Ga_0.3N_3.36 epoxy-bonded magnet were(BH)_max=93.1 kJ/m³and D=5.36 Mg/m³. It was found that the value of the Curie temperature, and the reversible temperature coefficients of the bonded magnet in Sm-FeCo-Ga-N compounds were better than those of Sm-Fe-Ga-N compounds.