Magnetic properties of spin valves with antiferromagnetic CrMnPt deposited at various Ar pressures

The dependence of the giant magnetoresistance (MR) ratio and exchange bias field (Hex) on the argon deposition pressure (PAr) of antiferromagnetic CrMnPt film for top spin valves was investigated. The MR ratio was enhanced from 5.0% to 8.3% as the PAr of CrMnPt film increased from 2 to 15 mTorr. Hex also increased from 150 to 300 Oe. These significant enhancements in the magnetic properties were correlated with microstructural changes and body-centered-tetragonal (bct) phase change reaction in the antiferromagnetic film. The bct phase change was promoted at high PAr because of the microstructural defects. The blocking temperature (TB) and the exchange anisotropy energy (Jex) were higher at high PAr owing to the promotion of bct phase change.