Evidence of the Inhomogeneous Ce3+ Distribution across Grain Boundaries in Transparent Polycrystalline Ce3+-Doped (Gd,Y)(3)Al5O12 Garnet Optical Ceramics

This paper characterizes the inhomogeneous rare earth activator distribution across grain boundaries in transparent rare earth doped optical ceramics. Ce3+ has been selected due to its high intensity fluorescence in visible range under blue or UV excitations, especially in (Gd,Y)(3)Al5O12 disordered garnet ceramic for scintillator application. Optical spectroscopy and visualization of grains and grain boundaries based on spatially resolved techniques as imaging confocal microscopy (ICM) and transmission electronic microscopy (TEM) have been used for 0.5% Ce3+-doped (Gd,Y)(3)Al5O12 ceramic. A strong Ce3+ segregation and spatial distribution between grains and grain boundaries were observed. (C) 2010 The Japan Society of Applied Physics