Electroless-deposited soft magnetic underlayer on silicon disk substrate for double-layered perpendicular magnetic recording media

• Published in: Journal of magnetism and magnetic materials Vol. 287; pp. 292 - 297
• Main Authors: Osaka, T., Asahi, T., Yokoshima, T., Kawaji, J.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2005; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electroless deposition; Exact sciences and technology; Magnetic properties and materials; Perpendicular magnetic recording medium; Physics; Silicon disk; Soft magnetic underlayer; Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.); Studies of specific magnetic materials; Perpendicular magnetic recording medium; Soft magnetic underlayer; 75.50.Ss; 82.45.Aa; Silicon disk; Electroless deposition; Mechanical polishing; 82.45.Aa Perpendicular magnetic recording medium; Domain walls; Chemical polishing; Soft magnetic materials; Domain structure; Magnetic domains; Magnetic structure; Recording material; Nickel; Silicon; Double layers
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2004.10.086

A novel fabrication process of a soft magnetic underlayer (SUL) for a double-layered perpendicular magnetic recording medium was presented. The CoNiFeB SUL was deposited on a silicon disk substrate using an electroless deposition. The Ni seed layer for the electroless deposition was prepared by an electrochemical process. The surface of the deposited SUL was subjected to a chemical mechanical polishing to be flattened, and Ra value of the SUL was less than 0.4nm. A magnetic domain structure greatly depended on the electroless deposition condition. Particularly, the control of an agitation speed during electroless deposition is much effective for the suppression of distinct domain walls appearing in CoNiFeB underlayers.