The growth and investigations of electromechanical properties of Fresnoite Ba2Si2TiO8 crystal as a function of orientation

Large sized Fresnoite Ba2TiSi2O8 single crystals were grown by the Czochralski method. Using coordinate transformation methods, the relative dielectric, piezoelectric and elastic constants of Fresnoite Ba2TiSi2O8 as a function of orientation were investigated, and their two- and three-dimensional spatial distributions are presented. From them, the maximum values of the piezoelectric coefficients and the corresponding rotation angle can be obtained. The maximum values of coefficients d*(22); d*(23); d*(24); d*(32); d*(33) and d*(34) were achieved for rotation angles of 40 degrees, 32 degrees, 0 degrees, 58 degrees, 50 degrees and 90 degrees, respectively, and are on the order of 8.7, -4.7, 17.5, 4.7, 8.7 and 17.5 pC/N, respectively. Furthermore, the validity of the electromechanical properties investigation as a function of orientation was verified. The relative dielectric permittivity, elastic constant and piezoelectric coefficient of a ZXl50 degrees cut rod were calculated and found to be 14.1, 8.7 pC/N and 11.2 pm(2)/N, respectively, in good agreement with the experimental values of 12.7, 9.1 pC/N and 11.7 pm(2)/N. This investigation is important in providing direction for theoretical research and device design of piezoelectric Ba2TiSi2O8 crystals. (C) 2018 Elsevier B.V. All rights reserved.