STRUCTURE OF AMORPHOUS TbFeCo THIN FILMS PREPARED BY FACING TARGETS SPUTTERING

The dependences of structural and magneto-optical properties of amorphous TbFeCo films on Ar gas pressure PAr and deposition rate Rd have been investigated. The film specimens were prepared by Facing Targets Sputtering system. When Rd was in the range of about 50 nm/min, the film deposited at PAr below 6 mTorr showed the magnetization perpendicular to the film plane, while the one at PAr of 15 mTorr revealed the in-plane magnetization. TEM micrographs showed that the film prepared at PAr of 5 mTorr and Rd of 50 nm/min exhibited a columnar structure composed densely of fine particles. In the case of this study, higher Rd up to 300 nm/min resulted in a narrower range of Tb content with which the films had strong perpendicular magnetic anisotropy enough to exhibit magnetization perpendicular to the film plane. Read/write characteristics for the MO disk were evaluated. The C/N ratio of 51.6 dB (at bit length of 1.33 m) and the writing power of 5.0 mW were obtained.