Electrostrictive properties of nanosize PbTiO3

Properties of nanosize PbTiO3 are discussed from the standpoint of the effe cts of crystallite size on electrostrictive behavior. Experimental results based on crystallite size-dependent primary and secondary order parameters (spontaneous polarization and strain) show that the critical crystallite si ze (CCS) for the stabilization of the cubic paraelectric phase at 298 K is around 15 nm, The CCS inversely scales with the cubic-tetragonal transition temperature (T-tr). Electrostrictive coefficients exhibit an order of magn itude increase at 28 nm, which is attributed to the anharmonicity of the pe rovskite lattice. First order calculations indicate that the increase in th e electrostrictive coefficients offsets the decrease in spontaneous polariz ation. and results in an increase in piezoelectric moduli suggesting that p iezoelectric activity could, in principle, be observed in the nanosize regi me.