Spin-valve heads using CrMnPt antiferromagnetic films

Highly reliable spin-valve heads were developed using antiferromagnetic CrMnPt film. The exchange anisotropy energy J(K) for CrMnPt/Co as-deposited film was almost the same as that for CrMnPt/NiFe film. However, the J(K) doubled after annealing at a relatively low temperature of 230 degrees C. The annealing causes distortion in the crystal lattice of CrMnPt films, which is likely to be the cause of the enhancement of the J(K), The MR ratio and the exchange coupling field of spin-valve films with a structure of Ta(5)/NiFe(5)/Co(1) /Cu(2.5)/Co(3)/ CrMnPt(30) /Ta(5) (in nm) were 6.7% and 350 Oe, respectively. The CrMnPt-type spin-valve sensors are more resistant to electrostatic discharge (ESD) than IrMn-type spin-valve sensors. This is because of the higher blocking temperature of CrMnPt, The exchange coupling field H-UA in CrMnPt-type spin-valve sensors was thermally more stable than that in IrMn-type spin-valve sensors. Shielded spin-valve heads of a hard bias structure using CrMnPt antiferromagnetic film were fabricated. The readback waveform of the fabricated heads was noise-free and well biased. The output as normalized by the trackwidth was 800 similar to 1000 mu V/mu m, Spin-valve heads with CrMnPt were found to have an overall performance making them quite suitable for use in hard disk drives with an areal density higher than several giga bits/in(2).