Wear durability and structure of vacuum evaporated boron films

The effects of vacuum-deposited inorganic protective layers on wear durability were studied using a variety of sliders made of typical magnetic head materials. Boron protective layers are found to be the most suitable for combination with a MIG (metal-in-gap)-type ring head. Vacuum-deposited boron films provide durability comparable to that of sputtered-carbon or boron films. The structure of vacuum-deposited boron films is amorphous, and a thin (<5-nm) reacted/diffusion layer at the interface between boron and Co-Cr magnetic films is formed. Strong adhesion to magnetic film, homogeneous amorphous structure, and a thermal expansion coefficient similar to that of Co-based magnetic films are desirable properties that make boron films practical protective layers for thin magnetic-film media