Fabrication condition effects on the magnetic and magnetostrictive properties of sputtered Tb-Fe thin films

Abstract

Magnetic and magnetostrictive properties of amorphous Tb-Fe thin films are investigated as functions of sputtering conditions such as the substrate thickness, input power, sputtering time, and coverage area ratio of coated thin film to substrate. The observed magnetic and magnetostrictive properties are well explained in terms of the macroscopic tensile stress, which is formed due to the difference of the thermal expansion coefficients between the thin film and substrate, and an annealing effect. The macroscopic tensile stress enhances in-plane anisotropy, and the annealing effect mainly reduces local residual stress introduced during sputtering. At sputtering conditions corresponding to a high thin-film/substrate temperature, the macroscopic tensile and an annealing effect are high, causing the magnetostriction sensitivity to increase at low magnetic fields, coercivity, and remanence ratio.