Magnetic properties of sputtered anisotropic Pr–Fe–B thin films with different structures and antiferromagnetic materials

Anisotropic Pr–Fe–B films with soft-magnetic layer (Fe) and/or antiferromagnetic layer (Mn, FeMn or MnO) were prepared by direct-current (DC) magnetron sputtering on Si (100) substrates heated at 650 °C. The influence of four types’ different structures on the magnetic properties of Pr–Fe–B films was investigated. The phase and magnetic properties were characterized by means of X-ray diffraction (XRD) and superconducting quantum interference device (SQUID). Addition of antiferromagnetic layer enhances both the coercivity and the remanence ratios of Pr–Fe–B films with suitable structures. The interface number increases and the antiferromagnetic–ferromagnetic exchange interaction is likely to become stronger, which affect the improvement of magnetic properties. To further understand the influence of structures with soft-magnetic Fe layer and/or antiferromagnetic FeMn layer on the magnetic properties of Pr–Fe–B hard-magnetic films, the thickness of Pr–Fe–B layer was designed to decrease from 600 to 50 nm. The improvement of magnetic properties becomes obvious in Mo(50 nm)/Pr–Fe–B(25 nm)Mo(2 nm)FeMn(20 nm)Mo(2 nm)Pr–Fe–B(25 nm)/Mo(50 nm) film.