Obliquely sputtered TbFe giant magnetostrictive films with in-plane anisotropy

We have found that in-plane magnetostriction characteristics at low fields can be greatly improved by an oblique sputtering technique. We report a study of deposition of in-plane anisotropic TbFe giant magnetostrictive films by dc magnetron oblique sputtering, including the influences of deposition angle on TbFe film magnetic and magnetostrictive performances. The in-plane magnetization of TbFe films at 1600 kA/m is drastically increased with a change of deposition angles from 90° to 15°. Magnetic domain structures explored by magnetic force microscopy indicate that the easy magnetization directions of the films can be gradually changed from perpendicular to the film plane at sufficiently shallow deposition angles. The in-plane magnetostrictive coefficients λ at 16 kA/m also can be increased by decreasing the deposition angles from 90° to 15°. The significant variation in the in-plane magnetic and magnetostrictive performances can be explained by the decrease of perpendicular anisotropy of TbFe films.