Pressure Effects on Magnetic and Transport Properties in CoFe-Based Spin Valve

Abstract

We have studied the magnetoresistance of an enhanced-biased spin valve device under high pressure. The magnetoresistance decreases by 0.0014 up to 2 GPa with increasing pressure, which is inferred to be due to slight deviation from an antiparallel-spin configuration of the free and pinned layers. In the pressure range between 2 and 2.75 GPa, the exchange bias field generated in the pinned layer decreases and the coercivity of the free layers clearly increases by ∼5 Oe, which is likely to be related to less hydrostatic pressure.

Fig. 1 Magnetoresistance of the exchange-biased spin valve device at room temperature under high pressure. The resistance, R is normalized by that at +1200 Oe, R_P. The R/R_P of the antiparallel configuration of the pinned (P) and free (F) layers in the magnetic field range between −500 Oe and 0 Oe is suppressed gradually with increasing pressure.