Effects of residual strain on magnetoresistance in heterostructures of La0.9Ca0.1MnO3/0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3

- Epitaxial thin films of La0.9Ca0.1MnO3 were grew on (100) orientedPMN-PT single-crystal substrates.
- The ferroelectric poling induces decreased in-plane tensile strain in the La0.9Ca0.1MnO3 film.
- The lattice strain significantly affected the magnetoresistance of La0.9Ca0.1MnO3.

Epitaxial thin films of La0.9Ca0.1MnO3 were grown on (100) oriented 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) single-crystal substrates by pulsed laser deposition. The heterostructure composed of manganite and ferroelectric would enable us to control and study the electric/magnetic properties of manganite by means of tunable strain induced via the piezoelectric effect of PMN-PT. X-ray diffraction revealed that the ferroelectric poling remarkably modify the in-plane tensile strain introduced in the La0.9Ca0.1MnO3 film, which gives rise to tune resistance and Curie temperature TC. It is also found that due to poling of PMN-PT the magnetoresistance of La0.9Ca0.1MnO3 is reduced in the paramagnetic state, but increased in ferromagnetic state. The observed effects of residual strain on magnetoresistance could be explained by the Jahn-Teller distortion and polarization effect on the coexistence of multiple phases.