Improvement of giant magnetoresistance properties of CrMnPt spin valves by dc magnetron sputtering

CrMnPt spin valve films with high a giant magnetoresistance (GMR) ratio of 14% were fabricated using dc magnetron sputtering. The switching field is above 700 Oe and the blocking temperature is 320 °C for a 250 Å CrMnPt pinning layer in a simple top spin valve stack. The exchange interfacial coupling constant is of 0.22 erg/cm2 which is much higher than that of the rf sputtered films. The as-made spin valve shows an abnormal resistance transition below the blocking temperature of 150 °C. The results indicate that the deposition method can influence the GMR properties greatly through the modification of the microstructure.