Offtrack characteristics on media noise for Co-Cr-Ta films

The effect of remanent magnetic flux density (B_r) and magnetic layer thickness (δ) on offtrack noise characteristics in Co-Cr-Ta alloy thin films is investigated. It has been found that decreasing the value of B_r is a more effective method of improving offtrack noise characteristics than decreasing the value of δ. Offtrack noise is shown to be due to the fluctuations in the amplitude of readback waveforms, fluctuations which are caused by fluctuations in magnetic transition amplitude. It was observed, using a magnetic force microscope, that lower B_r media had sharp boundaries at the track edge regions and the magnetization was more uniform, compared with those of higher B_r media