Large LFMR observed in twinned La2/3Ca1/3MnO3 thin films epitaxially grown on YSZ-buffered SOI substrates

TL;DR

This study demonstrates large low-field magnetoresistance in twinned La2/3Ca1/3MnO3 thin films grown on YSZ-buffered SOI substrates, highlighting potential for magnetic sensor applications.

Contribution

It reports the growth and characterization of epitaxial La2/3Ca1/3MnO3 films on YSZ-buffered SOI, revealing significant LFMR due to twin boundaries and anisotropies.

Findings

Resistance change of ~20% at <1000 Oe and 50 K

Presence of multi-domain epitaxy and twin boundaries

Large LFMR attributed to spin-dependent tunnelling

Abstract

La2/3Ca1/3MnO3 thin films have been grown on yttria-stabilized zirconia (YSZ) buffered silicon-on-insulator (SOI) substrate by the pulsed laser deposition technique. While full cube-on-cube epitaxy was achieved for the YSZ layer, the top manganite layer was multi-domain-oriented, with a coexistence of cube-on-cube and cube-on-diagonal epitaxy. Due to a combined influence from the magnetocrystalline anisotropy and the magnetoelastic anisotropy, in zero field the local spin orientation varies across the twin boundaries. As a result, a quite large low-field magnetoresistance (LFMR) based on spin-dependent tunnelling was observed. The film shows a resistance change of ~20% in a magnetic field <1000 Oe at 50 K, which is promising for real applications.