Elsevier, Journal of Alloys and Compounds, 5(509), p. 1756-1759
DOI: 10.1016/j.jallcom.2010.10.034
Full text: Unavailable
Single crystals of LaGaO3 doped with Sr and Mn (LSGMn) were grown by the Czochralski method from the melt with compositions: La1−xSrxGa1−yMnyO3, x=y=0.02; 0.05 and x=0.05, y=0.06. Single crystals with 20mm diameter with convex crystal–melt interface were grown on LaGaO3 oriented seed with pulling rate of 2mm/h. Single crystals were dark and have strong tendency to spiral growth. This tendency was decreased with increasing the Mn content in comparison with Sr. Effective segregation coefficients for Sr and Mn in LaGaO3 are lower than 1. Room-temperature structural measurements by X-ray powder diffraction showed perovskite structure with Pbnm space group for all measured samples. Orthorhombic b and c lattice parameters decrease, whereas a slightly increases with decreasing orthorhombic unit cell volume that is related to increased amount of Mn and Sr in the melt. Thermal analysis and Raman investigations showed that the temperature of the first order phase transitions temperature form orthorhombic to rhombohedral structure observed in pure LaGaO3 at about 150°C decreases to about 49°C at the bottom part of crystal with x=y=0.05 composition.