title: Confocal Raman microscopy across the metal-insulator transition of single vanadium dioxide nanoparticles.
abstract: We present the first Raman scattering measurements on nanoparticulate vanadium dioxide (VO(2)), as well as the first observations of the temperature-induced phase transition in individual VO(2) nanoparticles (NPs). We compare the Raman response of two VO(2) NPs and a companion VO(2) film undergoing their monoclinic-tetragonal-monoclinic transformations and offer qualitative explanations for the large observed differences in hysteresis width. While bulk crystals and contiguous films contain numerous nucleation sites, individual NPs likely harbor only a few, which may make it possible to correlate detectable defects (e.g., grain boundaries and dislocations) with the "ease" of switching phases, as quantified by the width of the thermal hysteresis.
authors.affiliation: Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA. eugene.donev@uky.edu
authors.forename: Eugenii U
authors.initials: EU
authors.lastname: Donev
authors.forename: Rene
authors.initials: R
authors.lastname: Lopez
authors.forename: Leonard C
authors.initials: LC
authors.lastname: Feldman
authors.forename: Richard F
authors.initials: RF
authors.lastname: Haglund