Abstract-Geometric constraints on phase coexistence in vanadium dioxide single crystals

Christina McGahan1, Sampath Gamage2,3, Jiran Liang1,4, Brendan Cross2,3, Robert E Marvel5,6, Richard F Haglund1,5 and Yohannes Abate2,3

Published 18 January 2017 • © 2017 IOP Publishing Ltd 

http://iopscience.iop.org/article/10.1088/1361-6528/aa5652

The appearance of stripe phases is a characteristic signature of strongly correlated quantum materials, and its origin in phase-changing materials has only recently been recognized as the result of the delicate balance between atomic and mesoscopic materials properties. A vanadium dioxide (VO2) single crystal is one such strongly correlated material with stripe phases. Infrared nano-imaging on low-aspect-ratio, single-crystal VO2 microbeams decorated with resonant plasmonic nanoantennas reveals a novel herringbone pattern of coexisting metallic and insulating domains intercepted and altered by ferroelastic domains, unlike previous reports on high-aspect-ratio VO2 crystals where the coexisting metal/insulator domains appear as alternating stripe phases perpendicular to the growth axis. The metallic domains nucleate below the crystal surface and grow towards the surface with increasing temperature as suggested by the near-field plasmonic response of the gold nanorod antennas.