OCCURRENCE OF LARGE PERPENDICULAR MAGNETIC ANISOTROPY IN BILAYERED FILMS WITH NANOMETER-THICK TBFECO AND AL LAYERS

For Tb‐Fe‐Co(MO)/Al bilayered films, dependence of perpendicular magnetic anisotropy constant K u ⊥ on MO layer thickness t MO of 3–300 nm and Al layer thickness t Al of 5 and 100 nm has been investigated. For either t Al, easy magnetization direction was normal to film plane at t MO above 4 nm. K u ⊥ of films with t Al of 5 nm increased drastically with increasing t MO for t MO<10 nm and then assumed a constant value of 4×106 erg/cm3 which is two times larger than that with t Al of 100 nm. This difference in K u ⊥ between them may be attributed to stress induced anisotropy. Estimation of rotational hysteresis loss W r and its integral R suggests that the mechanism of magnetization reversal may be attributed to incoherent curling mode.