Increase of coercivity and squareness ratio of by ferrite thin films by adding SiO/sub 2/ and substituting Al for Fe

Abstract

Simple Ba ferrite (BaM) and SiO 2 -added BaM (BaM:SiO 2 ) and Al substituted BaM (Al-BaM) films were deposited using the facing targets sputtering apparatus on SiO /Si wafers with Pt seed layers to enhance the -axis orientation perpendicular to the film plane. Magnetic characteristics of the three kinds of BaM films were investigated and compared. Perpendicular coercivity and squareness ratio of BaM:SiO 2 films increased to 4.2 kOe and 0.83, respectively. and of Al-BaM films increased to 3.2 kOe and 0.89, but saturation magnetization decreased to 2.9 kG. The magnetization reversal mechanism of BaM:SiO 2 and BaM films is not in coherent rotation mode but seems to be in the curling mode. The reason for high of BaM:SiO 2 films is different from that of Al-BaM ones.

Orientation Control and Domain Structure of Epitaxial (Ni,Zn)Fe₂O₄ Thin Film for Ferromagnetic Memory Applications

“…1(b)). The reason why SiO 2 doped-NZF thin film was prepared was that significant improvement of squareness have been reported for Ba-ferrite (BaFe 12 O 19 ) [6]. The amount of SiO 2 addition was 0-5 mol% of NZF.…”