THIN FILM MAGNETOSTRICTOR AND METHOD FOR MANUFACTURING THE SAME

To provide a thin film magnetostrictor having a high magnetic strain λs even if being applied to a thin film having a small thickness.SOLUTION: A thin film magnetostrictor has a thin film. The thin film contains Fe, Co, Tb and O primarily. The thin film has a surface-inclined composition film, an inside-uniform composition film, and an inside-inclined composition film. The inside-inclined composition film, the inside-uniform composition film and the surface-inclined composition film are located in this order from a substrate on which the thin film is formed toward an outermost surface of the thin film. The inside-uniform composition film is in contact with the inside-inclined composition film and the surface-inclined composition film. When the atomic number ratio calculated by (Co concentration+Fe concentration)/(Tb concentration) is represented by (Co,Fe)/Tb, the average value of (Co,Fe)/Tb in the inside-uniform composition film is 4.0 or more and 6.0 or less. The maximum of (Co,Fe)/Tb in the inside-inclined composition film is over 100.SELECTED DRAWING: Figure 2 【課題】 膜厚が小さい薄膜に適用する場合でも高い磁歪λｓを持つ薄膜磁歪素子を提供することを目的とする。【解決手段】 薄膜を有する薄膜磁歪素子である。薄膜はＦｅ，Ｃｏ，ＴｂおよびＯを主に含む。薄膜が表面傾斜組成膜と、内部均一組成膜と、内部傾斜組成膜と、を有する。薄膜が形成される基板から薄膜の最表面に向かって、内部傾斜組成膜、内部均一組成膜、表面傾斜組成膜の順番に位置する。内部均一組成膜は、内部傾斜組成膜および表面傾斜組成膜と接する。（Ｃｏ濃度＋Ｆｅ濃度）／（Ｔｂ濃度）で算出される原子数比を（Ｃｏ，Ｆｅ）／Ｔｂとして、内部均一組成膜における（Ｃｏ，Ｆｅ）／Ｔｂの平均値が４．０以上６．０以下である。内部傾斜組成膜における（Ｃｏ，Ｆｅ）／Ｔｂの最大値が１００を超える。【選択図】 図２