High density recording characteristics of sputtered barium ferrite thin films

We report the recording characteristics of in-situ crystallized sputtered barium ferrite (BaFe/sub 12/O/sub 19/, BaM) thin film media grown on a SiN coated carbon substrate. Using an inductive head with a gap of 0.27 /spl mu/m at a flying height of 0.1 /spl mu/m, a linear density, D/sub 50/, of more than 100 kfci was obtained. The pulse width, PW/sub 50/, was measured to be 0.35 /spl mu/m. In contrast to Co alloy media, BaM media do not exhibit superlinear noise behavior, indicating non-exchange coupled grains. A model of decoupled grain assembly was used to calculate signal to noise ratio (SNR), giving calculated values in very good agreement with the experimentally measured values. In addition, the magnetic property optimization of sputtered BaM media was also investigated.