| 摘要 |
PROBLEM TO BE SOLVED: To obtain a nonmagnetic base material by adding a specific material to La2 O3 , CoO and NiO and baking, having magnetic head characteristics as a magnetic thin film, suitable as a material requireng a high thermal expansion and to improve environmental resistance, fine processability and reliability. SOLUTION: La2 O3 in an amount of 15-35mol% calculated as LaO3/2 , 40-60mol% of CoO, 15-35mol % of NiO and 0.1-20mol % of one or more of Al2 O3 , Y2 O3 , SiO2 , ZrO2 and TiO2 are weighed as raw materials, mixed by a wet ball mill, dried, and calcined at 700-1,000C. The prepared calcined material is ground, mixed with about 1 % of a PVA-based organic binder and granulated to give a compact. The compact is sintered in the atmosphere, in nitrogen or in their mixed atmosphere at 1,200-1,400 deg.C, further subjected to hot isostatic pressing (HIP) treatment at about 1,250 deg.C under 1,000-1,500 atmospheric pressure to give a nonmagnetic bases material having 140-200×10<-7> / deg.C coefficient of thermal expansion, 500-1,200kgf/mm<2> Vickers hardness and <=5mm crystal grain diameter. The nonmagnetic material is used to give a magnetic head. |
