Strain tunability of the downward effective polarization of mechanically written domains in ferroelectric nanofilms

摘要: Nano 180° domains written by local mechanical force via the flexoelectric effect have recently attracted great attention since they may enable applications in which memory bits are mechanically. Downward effective polarization (DEP), i.e., net downward-pointing zone underneath pressure-surface contact area, is expected to be large for clear storage and readout of bits. Here, strain tunability DEP mechanically investigated using a multi-field coupling model effect. The PbTiO3 films grown on five different substrates examined. It found that, when not enough writing process with largest tensile misfit reach steady state, domain increases as changes from being compressive tensile. In contrast, applied sufficiently opposite. latter case, reduction mainly ascribed decrease field, reflected asymmetry polarization-electric field hysteresis loops under force. Our work suggests that strains useful improving DEP.