Near-room-temperature tunneling magnetoresistance in a trilayer La0.67Sr0.33MnO3/La0.85Sr0.15MnO3/La0.67Sr0.33MnO3 device

Abstract

A trilayer La0.67Sr0.33MnO3/La0.85Sr0.15MnO3/La0.67Sr0.33MnO3 tunneling magnetoresistance (TMR) device has been epitaxially produced on a SrTiO3 substrate. The current–voltage curves show that tunneling process dominates the carrier transfer across the junction near room temperature. However, the tunneling effect becomes weak with decreasing temperature. Magnetoresistance of about 4%–6% has been observed below room temperature. The temperature dependence of TMR appears correlated to both the tunneling effect cross the junction and the spin polarization in La0.67Sr0.33MnO3 layers. The temperature dependence of the TMR effect in this device is different from that of other devices based on colossal magnetoresistance materials.