Synergistic optimization mechanism of microstructure and magnetic properties in M-type strontium ferrite via Ce/La co-doping and pre-sintering temperature regulation

• • CeO2/La2O3 mass ratio of 2:8 significantly improves main phase purity and lattice stability, suppressing abnormal grain growth and enhancing coercivity via charge compensation and lattice stress modulation. • • Pre-sintering at 1180°C yields optimal grain size and densification, leading to enhanced magnetic exchange coupling and achieving remanence of 413 mT and intrinsic coercivity of 298 kA/m. • • The synergistic effect of Ce/La co-doping and pre-sintering temperature enables a balanced magnetic performance, with coercivity increased while maintaining sufficient remanence and stable saturation magnetization. • • The optimized processing window (2:8 ratio, 1180°C) provides a scalable route for producing environmentally friendly, high-performance rare-earth-free permanent magnets, addressing cost and sustainability bottlenecks.