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 degrees C for a 250 A CrMnPt pinning layer in a simple top spin valve stack. The exchange interfacial coupling constant is of 0.22 erg/cm(2) 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 degrees C. The results indicate that the deposition method can influence the GMR properties greatly through the modification of the microstructure. (C) 2000 American Institute of Physics. [S0021-8979(00)93908-2].