Yuuji Omata

Formation of Ni-Zn-Ferrite Films Using Laser Ablation

Ni-Zn-ferrite thin films were formed on glass substrate by a laser ablation method employing a KrF excimer laser at wave-length 248 nm and frequency 15 Hz. Film was deposited on substrate at room temperature, 200°C and 350°C, to a thickness of 2 ¿m. Ni-Zn-ferrite films thus prepared had the spinel structure when the substrate temperature was raised to 200°C. The saturation magnetic flux densities of Ni-Zn-ferrite films annealed at 400°C were between 1300 and 2020 G. The coercive force of annealed Ni-Zn-ferrite films decreased from 534 to from 70 to 113 Oe as the N2O gas pressure was decreased from 1×10¿2 Torr to 1×10¿5 Torr.

Magnetic properties of Fe-Co-Ni films with high saturation magnetization prepared by evaporation and electrodeposition

The Fe-Co-Ni based alloys have long been known as a soft magnetic material (perminvar alloy) which contains the features of high saturation magnetization exceeding 20 kGauss and a permanent permeability. However, there have been few reports on its wide composition range in relation to thin film materials. Fabrication possibilities have been confirmed over a wide composition range in regards to the Fe-Co-Ni based thin films based on the evaluation of the Fe-Co-Ni based thin film structure and magnetic properties with the sputtering evaporation method and alloy electrodeposition which employs the electrolytic plating method. Thus, in this report, we have focused on an examination of the relationship of the preparation method centering around composition adjustment with the film structure and magnetic properties. In regards to the high Bs compositions, the soft magnetic properties and corrosiveness of the electrodeposition films which have been formed in minute regions are examined and practical application to thin film head material has been examined.