Abstract:Abstract: BiFeO3(BFO) and Sr1-xLaxFe12-xCoxO19（x=0~0.3）monolayer films and 2-2 BiFeO3 / Sr1-xLaxFe12-xCoxO19 stacked composite films were prepared on the P-type <100> Si-based substrates by magnetron sputtering at room temperature. The microstructure, surface morphology and magnetic properties of thin film samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and material properties of a comprehensive test system (PPMS).The results indicate that with the increase of x, the coercive force of Sr1-xLaxFe12-xCoxO19 monolayer first increase after small decreases, residual magnetism ratio unchanged at first and then increase, while the residual magnetization have been reduced. When the x = 0.3 the coercive force and the residual magnetism ratio reached a maximum value of 6165Oe and 0.69, and the residual magnetization reaches the minimum value of 50emu/cm3; The coercive force and residual magnetism ratio of the composite film decreases after the first increases, while the residual magnetization have been reduced. At x = 0.2 the coercive force and residual magnetism ratio reached a maximum value of 5333Oe and 0.73. When the x = 0.3 when the ratio of the coercive force and the residual magnetism ratio decreased significantly as 2151Oe and 0.4, the residual magnetization in this case is the minimum value of 19 emu/cm3.