Room-temperature tunneling magnetoresistance in La0.7Sr 0.3MnO3 step-edge junctions
Journal
Journal of Applied Physics
Journal Volume
95
Journal Issue
9
Pages
4928-4933
Date Issued
2004
Author(s)
Abstract
La 0.7 Sr 0.3 MnO 3 tunneling magnetoresistance (TMR) junctions have been fabricated on step-edge (001) SrTiO3 substrates with a high step-edge angle. The step-edge junctions show nonvanishing TMR spikes in R(H) curves above room temperature (RT). The resistance, dynamic conductance, and TMR ratio are characterized to explore the possible conduction mechanism for the step-edge junctions. The temperature dependence of surface magnetization MS(T) deduced from the spin polarization P(T), following a (Tc−T)0.92±0.02 dependence, agrees with the theoretical models for MS(T). From these results, we conclude that tunneling is the dominating mechanism and that the charge carriers at the surface boundary govern the tunneling conductivity.
Type
journal article