Strain modification of epitaxial perovskite oxide thin films using structural transitions of ferroelectric BaTiO₃ substrate

Effects of induced biaxial strain on the electrical transport and magnetic properties of epitaxial thin films of SrRuO₃ and La_0.67Sr_0.33MnO₃ by structural transitions of ferroelectric BaTiO₃ substrates have been studied. Large jumps of electrical resistivity (∼5% in SrRuO₃ and ∼12% in La_0.67Sr_0.33MnO₃) and low field magnetization (∼70% in La_0.67Sr_0.33MnO₃) have been observed in the films at the structural transition temperatures of BaTiO₃ substrate. The hysteretic jumps are reproducible through many thermal cycles, and they can be attributed to strain effects induced by the substrate. The use of phase transitions of ferroelectric substrates to manipulate lattice strain of epitaxial thin film heterostructures can be a useful way to modify the properties of perovskite oxides. © 2000 American Institute of Physics.