Glass-ceramic substrates for 1 Gb/in/sup 2/ and beyond

Glass-ceramic substrates based on the lithium silicate system have been found to have excellent tribological performance, associated with the inherent bump topography produced by differential polishing of /spl alpha/-quartz and a lithium silicate/glass matrix. This paper explores the extendibility of lithium silicate alternative substrates to meet the needs of recording media for use at densities approaching and exceeding 1 Gb/in/sup 2/. Flatness, topography, magnetic performance, and resistance to environmental attack are shown to be extendible to higher density, and alternatives to the inherent bump topography are presented.