Phase diagram and enhanced piezoelectricity in the strontium titanate doped potassium–sodium niobate solid solution

The dielectric and the piezoelectric properties of the (1–x)(Na0.5K0.5)NbO3–xSrTiO3 ceramics, densified by the Spark‐Plasma‐Sintering method, have been studied. A phase diagram was established from the temperature dependence of the dielectric constant. A tetragonal–orthorhombic morpho‐tropic phase boundary (MPB) was found at x ∼ 0.05. Around the MPB, piezoelectric properties were greatly improved. The origin for the enhanced piezoelectricity has been proposed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)