Complex hierarchical shapes are widely known in biogenic single crystals, but growing of intricate synthetic metal single crystals is still a challenge. Here we report on a simple method for growing intricately shaped single crystals of gold, each consisting of a micron-sized crystal surrounded by a nanoporous structure, while the two parts comprise a single crystal. This is achieved by annealing thin films of gold and germanium to solidify a eutectic composition melt at a hypoeutectic concentration (Au-enriched composition). Transmission electron microscopy and synchrotron submicron scanning diffractometry and imaging confirms that the whole structure was indeed a single crystal. A kinetic model showing how this intricate single-crystal structure can be grown is presented.
@article{arxiv.2001.02597,
title = {A gold complex single crystal comprised of nanoporosity and curved surfaces},
author = {Maria Koifman Khristosov and Leonid Bloch and Manfred Burghammer and Paul Zaslansky and Yaron Kauffmann and Alex Katsman and Boaz Pokroy},
journal= {arXiv preprint arXiv:2001.02597},
year = {2020}
}