Magnetic properties of SmCo-based permanent magnetic films during 25 to 300 °C

Magnetic properties of the SmCo-based permanent magnetic films prepared on hot substrate with Mo and Cr underlayer without subsequent annealing process were investigated by vibrating sample magnetometer (VSM), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS). The results showed that the film thickness of the SmCo-based films presented complex effect on the intrinsic coercivity Hci. Optimal Hci for the films with Mo underlayer, Cr underlayer, and without underlayer was observed with different film thicknesses. Furthermore, the monotonous temperature dependence of Hci was found to be strongly correlated with the magnetic parameters for the 3.0 μm thick SmCo7 films with Mo underlayer. From 25 to 300 °C, the Hci decreased from 281.6 to 211.2 kA/m with a temperature coefficient of −0.091%/°C, exhibiting good temperature stability.