Properties of sputter deposited film are depended on deposition process and deposition conditions with energetic ion bombardment. The energetic ion bombardment affects to characteristic on the growing film. In previously, we have studied the process dependence for magnetostrictive properties of films by using several film processes such as magnetron sputtering, ion beam sputtering and ion plating. Impingement of energetic ions to depositing film surface is a key factor for controlling of magnetostrictive properties. The effect of ion bombardment on magnetostrictive properties of films can be understood as change of magneto-elastic energy induced by internal stress propagated by ion bombardment during film deposition. In this study, ion bombardment effects on internal stress and magnetostrictive characteristics of sputtered Ni films ware quantitatively discussed by an ion bombardment parameter.

The ion bombardment parameter Pi is based on a momentum of bombardment ions per deposited atom of film materials [1]. The Pi of argon ions was determined using Langmuir probes during the sputter deposition.

The tensile stress of Ni film was increasing with increasing P_i dependence of sputter power. The saturated magnetrostriction of Ni film was increasing with decreasing P_i. The low tensile stress reached in increased in-plane magnetic anisotropy, resulting to the magnetrostriction was increased.

[1] Koji Makita, Mitsuaki Takeuchi, Masashi Sato, Hirohisa Uchida, Yoshihito Matsumura., Applied Surface Science 256 (2009) p.1265.