Multilayer Magnetic Recording Media Research Articles

Carbon-coated Non-magnetic Iron Oxide Particles for the Substrate of Multi-layered Magnetic Recording Media

Non-magnetic particles with finer size (less than 200 nm), higher dispersibility, higher blackness and lower electrical resistance are required to produce better multi-layered magnetic tape media which have non-magnetic substrate using non-magnetic sub-layer materials. A special method to prepare acicular hematite particles, whose cross-sectional diameter is about 150 nm, coated with carbon black using a surface modification agent is reported in this paper. Transmission electron microscopy photographs of carbon-coated hematite particles indicate that all of the carbon black is firmly bound to the surface in a distinct layer. The thickness of carbon-coating layer was about 1 to 2 nm if 15% by weight of carbon black is coated onto the particle surface.

Texture evolution in CoCrPtTa/Cr/NiAl magnetic recording media

Crystallographic textures in a CoCrPtTa/Cr/NiAl multilayer magnetic recording media were studied by electron diffraction. It was found that texture quality evolves through the thickness of the films. A large improvement of texture quality was discovered at the interface of the Cr and NiAl layers. Surprisingly, there remains a portion of randomly oriented grains in the CoCrPtTa layer, in addition to the anticipated grains of [101̄0] texture. The texture quality of the CoCrPtTa layer remains similar to that of the underlying Cr layer.

Magnetic properties and crystallography of double-layer CoCrTa thin films with various interlayers

In this work, the hysteretic properties and remanence curves of double-layer CoCrTa thin films with various interlayers (Al, Cu, Ag, and Cr) are investigated. It is found that the double-layer CoCrTa films with Cu or Ag interlayers have narrower switching field distributions but similar high coercivities, compared with the films with Cr interlayers. To understand the effects of interlayers on the magnetic properties, the crystallography of these multilayer thin films are studied. The results from this work show that Ag and Cu are strong candidates as interlayer materials in multilayer magnetic-recording media. >