We report on a low-damage method for direct and rapid fabrication of arrays of epitaxial BiFeO3(BFO) nanoislands. An array of aluminium dots is evaporated through a stencil mask on top of an epitaxial BiFeO3 thin film. Low energy focused ion beam milling of an area several microns wide containing the array-covered film leads to removal of the bismuth ferrite in between the aluminium-masked dots. By chemical etching of the remaining aluminium, nanoscale epitaxial bismuth ferrite islands with diameter ∼250 nm were obtained. Piezoresponse force microscopy showed that as-fabricated structures exhibited good piezoelectric and ferroelectric properties, with polarization state retention of several days.
Morelli, A., Johann, F., Schammelt, N., McGrouther, D., & Vrejoiu, I. (2013). Mask assisted fabrication of nanoislands of BiFeO3 by ion beam milling. Journal of Applied Physics, 113, 1-4. . https://doi.org/10.1063/1.4801904