An Analysis on Microstructural Growth Process in Electroless Conirep Films for Perpendicular Magnetic Recording Media

The segregated microstructure and the growth process of electroless CoNiReP films were examined using selective chemical etching and heat-treatment methods. The segregated condition in the film changes with an increase in the film thickness up to ca. 200 nm, while it keeps a constant nature with a further increase in the film thickness of up to 2 gm. In the region of thickness over 200 nm, the film consists of high-crystallized particles with 20 nm diam segregating in the nonmagnetic region with low crystallinity. Such a segregation is confirmed to occur from the nucleation stage before forming a continuous film, and the segregated structure is stable with heat-treatment up to 500°C.