Engineered spatial inversion symmetry breaking in an oxide heterostructure built from isosymmetric room-temperature magnetically ordered components

摘要: The oxide heterostructure [(YFeO3)5(LaFeO3)5]40, which is magnetically ordered and piezoelectric at room temperature, has been constructed from two weak ferromagnetic AFeO3 perovskites with different A cations using RHEED-monitored pulsed laser deposition. polarisation arises through the removal of inversion centres present within individual components. This symmetry reduction a result combining ordering on site, imposed by periodicity grown structure, appropriate orientations octahedral tilting characteristic perovskite units themselves, according to simple symmetry-controlled rules. robust against site interdiffusion between layers produces sinusoidally modulated occupancy that retains coupling translational point symmetries required produce polar structure. Magnetization magneto-optical Kerr rotation measurements show heterostructure's magnetic structure similar Evidence polarity was obtained second harmonic generation force microscopy measurements. Modeling piezoresponse allows extraction d33 (approximately 10 pC N−1) heterostructure, in agreement DFT calculations.