Spin-valve heads using CrMnPt antiferromagnetic films

Highly reliable spin-valve heads were developed using antiferromagnetic CrM nPt film. The exchange anisotropy energy J(K) for CrMnPt/Co as-deposited fi lm was almost the same as that for CrMnPt/NiFe film. However, the J(K) doub led after annealing at a relatively low temperature of 230 degrees C. The a nnealing 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 th e exchange coupling field of spin-valve films with a structure of Ta(5)/NiF e(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 elec trostatic discharge (ESD) than IrMn-type spin-valve sensors. This is becaus e 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 outpu t as normalized by the trackwidth was 800 similar to 1000 mu V/mu m, Spin-v alve heads with CrMnPt were found to have an overall performance making the m quite suitable for use in hard disk drives with an areal density higher t han several giga bits/in(2).