Abstract

Growth of YMn O3 on GaN (0001) using molecular beam epitaxy at temperatures greater than 850 °C resulted in the spontaneous formation of crystalline prisms, ranging from 20 to 60 nm in height and 50 to 500 nm in lateral size, surrounded by a 6 nm thick continuous YMn O3 film. The local dielectric properties were measured using scanning surface probe microscopy. The prisms were ferroelectric at room temperature and their ferroelectric properties were enhanced for taller prisms. This is consistent with these structures being less constrained than the continuous layer, which is clamped by the surrounding unpolarized film. © 2008 American Institute of Physics.