Structural Control of Electroless‐Plated Magnetic Recording Media by Underlayers

Abstract

The structural control of electroless-plated CoP film was investigated using underlayers of electroless-plated CoNiMnP and CoNiP films. The CoNiMnP film showed a high degree of orientation of the hcp Co c-axis normal to the film plane, whereas the CoNiP film hardly sl:owed any preferred orientation. The CoP film plated onto the CoNiMnP underlayer showed a high degree of preferred orientation, while the CoP film plated onto the CoNiP underlayer showed a low degree of preferred orientation. Thus, the microstructure of the CoP film is clearly influenced by the underlayer structure. In the case of the CoP film onto the CoNiMnP underlayer, an epitaxial-like growth was observed up to a thickness of 0.25 ~m, and this reduced to the intrinsic microstructure at a thickness of 0.5 ~rn. Recording characteristics were measured on the 5 in. flexible disks, fabricated by plating the high-oriented CoP film or the low-oriented CoP film with a ringtype head of a commercial VHS video head. Perpendicular recording was performed on the high-oriented CoP fihn to demonstrate the best characteristics. The use of an oriented underlayer is thus confirmed to be a useful method of controlling the structure of the magnetic film in addition to controlling the bath plating parameters.

Tapping Mode Atomic Force Microscopy Analysis of the Growth Process of Electroless Nickel‐Phosphorus Films on Nonconducting Surfaces

“…Microstructural and functional properties of electrolessdeposited films are influenced by various factors. In the case of the deposition on nonconductive surfaces, the process of catalyzing the substrate surface plays a key role in controlling these properties.l 5 We investigated this issue by using transmission electron microscopy (TEM) [6][7][8] and scanning tunneling microscopy (STM), S ' 10 and confirmed that the catalyzing process and/or the substrate material influences the initial structure of the film such as grain size. Although those methods are effective for microstructural analysis, they do not allow direct observation of the growth process on nonconductive surfaces.…”

Effect of Heat‐Treatment on the Magnetic and Structural Properties of Perpendicular Magnetic Anisotropy CoNiReP Films Produced by Electroless Deposition

“…The authors have developed electroless-plated CoNiReP films for perpendicular magnetic recording and have investigated their characteristics successively (1)(2)(3)(4)(5)(6)(7)(8). In our previous study (9), we reported that the magnetic and structural properties of the films change widely with changes in composition, and that the Co32Ni55Re6P7 film shows the largest perpendicular magnetic anisotropy.…”