A series of La_1-xSr_xGaO₃ solid solution single crystal with x equals 0, 0.04 and 0.12 were grown by the Czochralski method and with x equals 0.01, 0.06 and 0.1 by the floating zone method. The segregation coefficient of Sr in LaGaO₃ has been found to be k_eff (Sr) equals 1.25. The crystals were grown from the melt with stoichiometric Ga₂O₃ amount at a growth rate ranging from 2.5 mm/h for pure LaGaO₃ to 1.2 mm/h for La_0.88Sr_0.12GaO₃. The structure of these crystals was investigated by x- ray powder diffraction technique using CuK_(alpha ) radiation. The diffraction patterns were analyzed by Rietveld refinement method. Crystals with strontium concentrations from x equals 0 to 0.1 crystallizes adopting Pbnm structure. It was found that deviation from the ideal perovskite structure decreases with rising strontium concentration, finally reaching centrosymmetric Ibmm structure at x equals 0.12. Orthorombic unit cell parameters c and b decreases whereas a increases with x. Thermal analysis proved that the temperature of the first order phase transition observed in pure LaGaO₃ at 150 degrees falls to 126 degrees at x equals 0.01 and remains almost constant at higher x.

Date Published: 10 August 2001
PDF: 5 pages
Proc. SPIE 4412, International Conference on Solid State Crystals 2000: Growth, Characterization, and Applications of Single Crystals, (10 August 2001); doi: 10.1117/12.435870

Published in SPIE Proceedings Vol. 4412:
International Conference on Solid State Crystals 2000: Growth, Characterization, and Applications of Single Crystals
Antoni Rogalski; Krzysztof Adamiec; Pawel Madejczyk, Editor(s)