Nanoscale LuFeO ₃ : shape dependent ortho/hexa-phase constitution and nanogenerator application

In multiferroic LuFeO₃ the hexagonal (-h) phase is an intermediate metastable phase encountered during the amorphous to orthorhombic (-o) transformation and is ferroelectric in nature. Thus far it has only been stabilized in a substrate-supported few layered ultrathin film form. Herein we show that the surface-induced strain field intrinsically present in nano-systems can self-stabilize this phase and the hexagonal to orthorhombic phase constitution ratio depends on the shape of the nanomaterial. Thus, nanoparticles (nanofibres) strain-stabilize the o : h ratio of about 75 : 25 (23 : 77). The inclusion of nano-LuFeO₃ into PDMS renders impressive nanogenerator performance, consistent with the ferroelectric phase content.