The ferroelastic strain coupling is predicted in perovskite heterostructures by phase-field modeling and evidence the coupling by X-ray diffraction and soft X-ray scattering. By controlling both substrate and electrostatic boundary conditions, the solid control of 109° or 71°-type periodic domain structures has been demonstrated. The 71° BFO domain structures were grown on SrRuO 3 (SRO)-buffered (110) DyScO 3 (DSO) substrates by pulsed laser deposition at 720 °C with 100 mTorr oxygen and then the LSMO thin film were in situ deposited on BFO with 200 mTorr oxygen. The morphology and ferroelectric domain structure of 71° striped BiFeO 3 (BFO) ferroelectric domains and La 0.7 Sr 0.3 MnO 3 (LSMO) layers were mapped via PFM mode in Multimode VIII. The ferroelastic domain walls could modulate the strain variance in LSMO, leading to large anisotropic resistivity and even the coexistence of different transport states. These findings can be utilized to establish new multifunctional devices in other strongly correlated systems, involving the anisotropy of superconductivity, Hall effects, nonlinear optics, and other emergent behaviors.
- electronic anisotropy
- ferroelastic strain coupling
- multiferroic heterostructures