Structural phase transitions in SrTiO3 nanoparticles

Pressure dependent structural measurements on monodispersed nanoscale SrTiO3 samples with average diameters of 10 to ∼80 nm were conducted to enhance the understanding of the structural phase diagram of nanoscale SrTiO3. A robust pressure independent polar structure was found in the 10 nm sample for pressures up to 13 GPa, while a size dependent cubic to tetragonal transition occurs (at P = Pc) for larger particle sizes. The results suggest that the growth of ∼10 nm STO particles on substrates with significant lattice mismatch may maintain a polar state for a large range of strain values, possibly enabling device use.