  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.
