Magnetic properties of Fe/FeSi$_{2}$/Fe$_{3}$Si trilayered films prepared by facing targets sputtering deposition

Whereas giant magnetoresistance and tunnel magnetoresistance films generally employ nonmagnetic metal and insulator spacers, respectively, we have studied Fe$_{3}$Si/FeSi artificial lattices, in which FeSi$_{2}$ is semiconducting and its employment as spacers is specific to our research. For the formation of parallel/antiparallel alignments of layer magnetizations, the employment of ferromagnetic layers with different coercive forces is required. There have been few studies on the fabrication of Fe-Si system spin valves comprising ferromagnetic layers with different coercive forces. In this work, Fe$_{3}$Si and Fe were employed as ferromagnetic layer materials with different coercive forces. Fe/FeSi$_{2}$/Fe$_{3}$Si trilayered spin valve junctions by facing targets direct-current sputtering deposition combined with a mask method, and their electrical and magnetic properties were studied. An Fe$_{3}$Si layer was epitaxially grown on Si(111) substrate as a bottom layer. After that, An Fe layer with a large coercive force was deposited as a top layer, posterior to a FeSi$_{2}$ layer being deposited. From magnetization curves measured by a vibrating sample magnetometer, it was confirmed that the parallel and antiparallel magnetization alignments of ferromagnetic layers are clearly realized.