Growth of Ce-doped LGSO fiber-shaped crystals by the micro pulling down technique

Publication date: 15 February 2015
Source:Journal of Crystal Growth, Volume 412
Author(s): V. Kononets , O. Benamara , G. Patton , C. Dujardin , S. Gridin , A. Belsky , D. Dobrovolskas , A. Vaitkevičius , G. Tamulaitis , V. Baumer , K. Belikov , O. Sidletskiy , K. Lebbou
Ce-doped Lu2x Gd2−2x SiO5 (LGSO:Ce) fiber-shaped crystals (x = 0.5) were grown by the micro-pulling down (µ-PD) technique. To optimize the activator concentration for achieving the best scintillation parameters, the cerium concentration in the melt was varied in the range from 0.01 to 1.5 at.%. Distributions of Gd³⁺ and Ce³⁺ in LGSO:Ce crystals grown by the µ-PD and Czochralski (Cz) techniques were compared. The spatial distribution of cations across the LGSO:Ce scintillation crystals grown by the µ-PD technique is studied using wide-field microscopy under simultaneous excitation of two types of Ce-related centers and confocal microscopy under the selective excitation of Ce³⁺ in CeO6 crystallographic sites. It is revealed that the fiber-shaped crystals contain a single crystal core surrounded by crystalline material with a higher density of inclusions and cracks that are predominantly directed along the crystal axis. The formation of inclusions and cracks is interpreted by a nonuniform radial distribution of LGSO:CE cations.