Glide avalanche prediction from surface topography

As the head/disk spacing continues to decrease, the demand for thin film disks with glide capability below 20 nm becomes more pressing. As a consequence, the design of such media requires an ever increasing control of the surface topography to a nanometer level. This paper is an attempt to analytically predict the intrinsic glide capability of a textured disk, given the knowledge of its peak height distribution, as measured by a surface profilometer. This model also takes into account the long wavelength component of the topography, or waviness, by treating it as an independent variable lending to a broadening of the peak height distribution. This analysis also predicts relationships between various roughness parameters. Experimental data obtained on a total of 27 media surfaces of various types compare favorably to the theoretical predictions.