STRUCTURES AND MAGNETIC-PROPERTIES OF CO/TA MULTILAYERED THIN-FILMS

Co/Ta multilayered thin films (MLF) are fabricated using a radio frequency (RF) sputtering device. X-ray diffraction and transmission electron microscopy evidence that these film's possess good periodicity and crystal structures in both the Co layers as well as the Ta layers. Magnetic hysteresis loops are measured at room temperature in the directions parallel and perpendicular to the film plane. It is found that a tendency of perpendicular magnetic anisotropy is well developed when the Ta layer thickness is decreased. Furthermore, with decreasing period of MLF, the coercivity H(c) decreases and the squareness increases, namely, the magnetic properties become softer. The above behavior can be interpreted in terms of the structures of the multilayered thin films.