Strain tuning effects in perovskites
2019 Copyright All rights reserved. Strain is a powerful tool for tuning the magnetic, ferroelectric, multiferroic, and superconducting properties of perovskites due to the reconstruction of spin, orbit, and charge at the film-substrate interface. In this work we demonstrate both the dynamic and static strain tuning effects on the properties of strong electron correlated perovskite oxides. The static strain tuning example used is the epitaxial pseudo cubic SmFeO3 thin film on (100) Nb-SrTiO3. High-resolution transmission electron microscope images reveal the stress-induced structural distortion at the film/substrate interface. Both rectangular ferroelectric loops and piezoelectric force microscope images at room temperature indicate the presence of ferroelectric polarization. A strong ferromagnetic-like transition was observed at 185K. The coexistence of ferroelectric polarization and magnetic ordering reveals that the strained SmFeO3 is multiferroic. The dynamic strain tuning effect was demonstrated in a La2/3Ca1/3MnO3 film on BaTiO3 (BTO) substrate. A sharp drop in resistance and a magnetization anomaly have been observed in La2/3Ca1/3MnO3 film in the zero magnetic field at the BTO substrate structural-phase transition temperature, due to the substrate clamping/strain effect, which is confirmed by Raman scattering.