Effects of electric-field-induced piezoelectric strain on the electronic transport properties of La_0.9Ce_0.1MnO₃ thin films

The authors constructed multiferroic structures by growing La _0.9Ce_0.1MnO₃ (LCEMO) thin films on piezoelectric 0.68Pb(Mg_1/3Nb_2/3)O₃-0. 32PbTiO₃ (PMN-PT) single-crystal substrates. Due to the efficient elastic coupling at the interface, the electric-field-induced piezoelectric strain in PMN-PT substrates is effectively transferred to LCEMO films and thus, leads to a decrease in the resistance and an increase in the magnetoresistance of the films. Particularly, it was found that the resistance-strain coefficient [ΔR/_Rfilm/Δ^εzz_film] of the LCEMO film was considerably enhanced by the application of magnetic fields, demonstrating strong coupling between the lattice and the spin degrees of freedom. ΔR/_Rfilm/Δ^εzz_film at 122 K was enhanced by ∼ 28.8% by a magnetic field of 1.2 T. An analysis of the overall results demonstrates that the phase separation is crucial to understand strain-mediated modulation of electronic transport properties of manganite film/PMN-PT multiferroic structures.