The effect of the constituent metal layer thickness on the microstructure and magnetic properties of Fe/Y multilayers

Fe/Y multilayers with various Fe and Y layer thickness were prepared by electron-beam vapor deposition. The effect of the constituent metal layer thickness on the microstructure and magnetic properties of the films was investigated by transmission electron microscopy. Rutherford backscattering, X-ray diffraction and vibrating-sample magnetometer. The experimental results showed that a magnetic transformation from the ferromagnetic to superparamagnetic state in the iron layers occurred with decreasing Fe layer thickness to 1.4 nm in the Fe/Y multilayers. The saturation mag netization of the multilayers reduced significantly with decreasing Fe layer thickness and increasing Y layer thickness. It was also found that the Y layer can grow in an f.c.c. structure when its thickness was less than 11 nm in the Fe/Y multilayers.