Effects of substrate on the magnetic properties of epitaxial TbFe/sub 2/(111) films

The effects of substrate on the strains of epitaxial TbFe/sub 2/(111) films, and consequently on the magnetization orientation, have been studied. Thermal strain from differential thermal contraction between substrates and the TbFe/sub 2/ films is considered to be the dominant factor in determining the film strain. Therefore, Al/sub 2/O/sub 3/(112~0), MgO(111), and CaF/sub 2/(111) substrates with an epitaxial W(110) buffer layer have been used to grow the TbFe/sub 2/ films. The magnetisation of the TbFe/sub 2/ films on the Al/sub 2/O/sub 3/ and MgO substrates with a tensile thermal strain is in the film plane, but that on the CaF/sub 2/ substrate with a compressive thermal strain is in the out-of-plane direction. An unknown soft magnetic material has been found at the interfacial region of the TbFe/sub 2/ film and the W buffer layer.