Growth and Optical Properties of LaGaO3/SrTiO3 MixedCrystals

Abstract

Single crystals of La 1-x Sr x Ga 1-x Ti x O 3 solid solution with x = 0.01, 0.04 and 0.08 were grown by the Czochralski method and with x = 0.01 by the floating zone method. Large good quality single crystals were grown by the Czochralski method from a stoichiometric melt at a growth rate at about 2 mm/h up to x = 0.04. Lattice constants determined by X-ray analysis, being equal to: a = 5.503(1), b = 5.541(1) and c = 7.7829(1), differ by opposite a/b ratio (a/b>1 for pure LaGaO 3 ) from pure LaGaO 3 . Thermal analysis proved that the temperature of the first order phase transition observed in pure LaGaO 3 at 150 °C falls to 76 °C at x = 0.04 and remains almost constant at higher x. The observed fluorescence of 2 T 2 - 2 E transition of Ti 3+ in the crystals shows two bands centered at about 420 and 447 nm coming from excitation at 314, 340 and 384 nm absorption bands.