Dielectric properties of Ba1-xSrxTiO3 single crystal fibers grown by laser heated pedestal growth technique

Single crystal fibers of several compositions in the system (Ba1-xSrx)TiO3 (0.10 less than or equal to x less than or equal to 0.40) were grown for the first time using the laser heated pedestal growth (LHPG) technique. High quality crystals were obtained, especially for low Sr contents, yielding the dielectric characterization study. Free growth was performed using ceramic rods as feed and seed. The growth direction as observed at room temperature was related to the strontium content in the crystal. Higher concentrations of strontium tend to favor composition fluctuations but average nominal composition remained the same. Pinching effect of the three phase transformations (cubic-tetragonal, tetragonal-orthorhombic and orthorhombic-rhombohedral) was observed with increase of Sr2+ substitution for Ba2+. The increase in strontium content also resulted in a broadening of the cubic-tetragonal (m3m-4mm) transition peak of dielectric permittivity and a decreasing of the Curie constant in this system.