NONMAGNETIC SUBSTRATE FOR MAGNETIC HEAD AND ITS PRODUCTION

摘要

PURPOSE:To obtain a nonmagnetic substrate having a coefft. of thermal expansion which coincides with that of a magnetic film for high recording density and having high mechanical strength. CONSTITUTION:One or more kinds of compds. selected from among CoAl2O4, NiAl2O4, MgAl2O4 and MnAl2O4 are dispersed in NiO and the resultant material is used to obtain the objective nonmagnetic substrate having a Vickers hardness of >=720 and coefft. of thermal expansion >=120X10<-7>/ deg.C. The peeling of a magnetic film from the substrate and the cracking of the substrate at the time of machining are remarkably suppressed and an advantage of cosr effectiveness such as an enhanced yield is given.