Controlled growth of two-dimensional `single-crystal' hafnia network s by surface modulation

Two-dimensional 'single-crystal' hafnia networks were synthesized by the high temperature gas-solid reaction method. Transmission electron microscopy investigation shows that these networks exhibit micrometre-scale external dimensions and nanometre-scale holes and frame width. The formation of these novel structures is based on the vapour-solid growth mechanism, and the boron nitride deposited on the networks' surface plays a key role in the growth procedure by selectively influencing the growth rate of the crystal faces. This process involves the control of crystal surface properties and adsorption of the growth unit, and is extendable to the fabrication of nanosystems either in two dimensions or in three dimensions.