Substrate effects on the magnetic characteristics of sputtered media

The magnetic characteristics of C/CoNiCr/Cr longitudinal recording media on NiCuP-plated substrates and various Al-Mg alloy substrates were investigated and compared with the conventional NiP-plated substrates. It was found that the media on the NiCuP-plated substrates had a flatter envelope waveform. The error characteristics of the media directly sputter-deposited on the Al-Mg alloy substrate made from high-purity Al ground metal or by rapid solidification were almost the same as those of the media on the NiP substrates. The Al-Mg alloy substrate finished by electrolytic abrasive polishing exhibited a higher resistance to corrosion than that finished by diamond turning. >