CRYSTALLIZED LAYER-STACKED GLASS, AND GLASS SUBSTRATE FOR MAGNETIC DISK USING THE SAME

PROBLEM TO BE SOLVED: To provide crystallized layer-stacked glass in which a crystallized layer is stacked at least on a part of the surface in a glass base material, to provide crystallized layer-stacked glass in which the thickness of at least a part of a crystallized layer-stacked on the surface of a glass base material is different from that of the other part, to provide a glass substrate for a magnetic disk using crystallized layer-stacked glass, and to provide a glass substrate for a magnetic disk in which at least a part of the region in the edge face is provided with a crystallized layer. SOLUTION: A starting raw material to be the preform of glass and, as necessary, a prescribed amount of additive are weighed with an electronic balance so as to be mixed. The mixture is melted by a crucible, and is cooled to be formed into glass. The glass is reheated so as to stack a crystallized layer on the surface of the glass, and the main surface is partially polished, thus the crystallized layer-stacked glass is produced. Using the same, e.g., a glass substrate for a magnetic disk is produced. COPYRIGHT: (C)2007,JPO&INPIT