酸素イオン照射によるCo含有酸化鉄薄膜メディアの作製  [in Japanese] Preparation of Co-γFe_2O_3/NiO Thin-Film Media by Irradiation with Oxigen Ions  [in Japanese]

A new plasma oxidization method was introduced into the fabrication process of Co-γFe_2O_3/NiO thin-film magnetic recording media in order to transform CoOFe_3O_4/NiO films into Co-γFe_2O_3/NiO films. It was found that remarkably effective oxidization was achieved by utilizing oxygen ions generated in an electron-cyclotron-resonance (ECR) microwave plasma, promoting oxygen generation though the Penning ionization effect using metastable He atoms, and neutralizing samples. In the coventional oxidization method, CoOFe_3O_4/NiO films were heated up to over 300℃, and kept for 1 to 2 hours in air. The new plasma oxidization method shortened the processing time to 10 seconds and lowered the process temperature to 150℃.