Investigation of the tunnel magnetoresistance in junctions with a strontium stannate barrier

Abstract

We experimentally investigate the structural, magnetic and electrical transport properties of La${}_{0.67}$Sr${}_{0.33}$MnO${}_3$ based magnetic tunnel junctions with a SrSnO${}_3$ barrier. Our results show that despite the large number of defects in the strontium stannate barrier, due to the large lattice mismatch, the observed tunnel magnetoresistance is comparable to tunnel junctions with a better lattice matched STiO${}_3$ barrier, reaching values of up to 350% at T=5 K. Further analysis of the current-voltage characteristics of the junction and the bias voltage dependence of the observed tunnel magnetoresistance show a decrease of the TMR with increasing bias voltage. In addition, the observed TMR vanishes for T>200 K. Our results suggest that by employing a better lattice matched ferromagnetic electrode and thus reducing the structural defects in the strontium stannate barrier even larger TMR ratios might be possible in the future.

References in corpus (7)

• Nearly total spin polarization in La2/3Sr1/3MnO3 from tunneling experiments
• Misfit Strain Accommodation in Epitaxial ABO3 Perovskites: Lattice Rotations and Lattice Modulations
• Thickness dependent magnetotransport in ultra-thin manganite films
• Large magnetoresistance in bcc Co/MgO/Co and FeCo/MgO/FeCo tunneling junctions
• Data Storage: Review of Heusler Compounds
• Improved tunneling magnetoresistance at low temperature in manganite junctions grown by molecular beam epitaxy
• Metal-insulator transition on SrTiO${}_3$ surface induced by ionic-bombardment