Giant Electrostrictive Coefficient In Rapidly Cooled Nanodisordered Kta1-Xnbxo3 Lead-Free Single Crystals

The temperature dependent electrostrictive effect, with respect to increasing the cooling rate to a cooling temperature, was quantitatively investigated in potassium tantalate niobate (KTN) lead-free single crystals above and near Curie temperature (T-C). High work-function Pt electrodes are used to minimize the effect of charge injection, and the electric field induced displacement was measured with Michelson interferometry. It was found that a giant electrostrictive coefficient of 696 x 10(-16) m(2)/V-2 could be obtained at a high cooling rate of 0.75 degrees C/s to a temperature of T-C + 4.5 degrees C due to the evolution of polar nano-regions, which is one order of magnitude larger than the previously reported value in KTN crystals. This strengthens the realization of replacing toxic lead-based electrostrictive materials with environmentally friendly KTN materials in real world applications.