Magnetic recording characteristics of sputtered γ-Fe2O3thin flim disks

A thin film disk of γ-Fe2O3for high density magnetic recording has been developed. γ-Fe2O3films were prepared in a serial process from the reactive sputtering of on to α-Fe2O3reduced to Fe3O4and oxidized to γ-Fe2O3. A high coercive force of 700 Oe and a squareness ratio of 0.8 were attained for γ-(Fe0.955Ti0.025Co0.02)2O3. Recording characteristics of the disk were evaluated using a Mn-Zn ferrite head. The recording density D50reached 1,100 bits/mm (27,900 bpi), and the number of dropout errors at 50 % threshold level was less than 50 per surface. Stability versus temperature change and wear resistance were also evaluated.