Evidence for perpendicular magnetic anisotropy of Tb in Tb/Fe multilayers

The magnetic moment direction of Tb in an [Fe(40 Angstrom)/Tb(30 Angstrom)](3) multilayer has been studied by the low-temperature nuclear orientation technique in external magnetic fields applied along and perpendicular to the sample plane. A perpendicular magnetic anisotropy of the Tb magnetic moments has been found at zero external magnetic field and the mean misalignment angle has been estimated to be about 49 degrees with respect to the sample plane normal. The external magnetic field applied along the sample plane turned the Tb magnetic moments to the plane, without reaching any saturation even at B-ext = 8 T. A possible structure of misalignment within the Tb layer is discussed.