Variations of composition and dielectric properties of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal along growth direction

Abstract

The compositional dependent dielectric properties of [001]-poled Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal are investigated along the [011] growth direction. The variation of Pb(In1/2Nb1/2)O3, Pb(Mg1/3Nb2/3)O3, and PbTiO3 content of crystal boule with a length of 70 mm are found to be around 1.3%, 10.5%, and 9.9%, respectively. The rhombohedral-to-cubic or rhombohedral-to-tetragonal phase transition temperature is more than 120 °C for the composition with rhombohedral phase far away from the morphotropic phase boundary. The phase transition temperature of rhombohedral-to-tetragonal, rhombohedral-to-monoclinic/orthorhombic, and monoclinic/orthorhombic-to-tetragonal move to lower temperature and the tetragonal-to-cubic move to higher temperature along crystal growth direction. The tetragonal phase induced by [001]-poling, composition, and temperature can help to improve the piezoelectric properties and the induced monoclinic/orthorhombic phase can further improve and mainly contribute to the high piezoelectric properties. The phase diagram was established based on the composition and dielectric properties. At room temperature, the rhombohedral-monoclinic/orthorhombic phase boundary was found to be nearly PIN-PMN-0.34PT.