Polar state in freestanding strontium titanate nanoparticles

Abstract

Monodispersed strontium titanate nanoparticles were prepared and studied in detail. It is found that ∼10-nm as-prepared stoichiometric nanoparticles are in a polar structural state (possibly with ferroelectric properties) over a broad temperature range. A tetragonal structure, with possible reduction of the electronic hybridization, is found as the particle size is reduced. In the 10-nm particles, no change in the local Ti-off centering is seen between 20 and 300-K. The results indicate that nanoscale motifs of SrTiO 3 may be utilized in data storage as assembled nano-particle arrays in applications where chemical stability, temperature stability, and low toxicity are critical issues. © 2014 AIP Publishing LLC.