Recording characteristics of semi-hard Mn-Zn ferrite sputtered disks

Thin films of ferrite such as Co-γFe2O3and BaFe12O19are useful for magnetic layers in high density recording disks. However, they have to be deposited on the substrates at considerably high temperatures (e.g.,250 and 500°C, respectively). In this study, Mn-Zn ferrite films with relative high coercive forces have been prepared at substrate temperature as low as 100°C, using "Facing Targets Sputtering" apparatus. Their read/write characteristics have been evaluated by means of a conventional ring head. The reproduced signals exhibited dipulse waveforms with dipulse ratios of 0.3. A recording density D50of about 60kFRPI was attained.