Pressure-Induced Disordering in SnO2 Nanoparticles

Abstract

The high-pressure behavior of SnO2 nanoparticles (∼2.8 nm) was studied up to approximately 20 GPa using Raman spectroscopy in a diamond anvil cell and ab initio simulations. Above ∼7 GPa, the disordering, initially located at the surface, was found to propagate to the core of nanoparticles, ultimately leading to amorphous-like spectra. This observation can be interpreted as a disordering of the oxygen sublattice sensitively probed by Raman spectroscopy in contrast to powder X-ray diffraction techniques. The low-frequency mode can be related to the nanoparticle vibration as an elastic isotropic sphere motion. The pressure-induced shift of this mode allows for the constraining of the mechanical properties data reported in the literature.