Glass-ceramics having hexacelsian as a primary crystal phase, magnetic disk substrate and magnetic disk

摘要

A glass-ceramic has a hexacelsian as a primary crystal phase and is characterized by satisfying a relation of 0≦I(101)/I(110)≦1.5 when a diffraction intensity of (101) face of hexacelsian in an X-ray diffraction is I(101) and a diffraction intensity of (110) face thereof is I(110).