Evidence of the Inhomogeneous Ce3+Distribution across Grain Boundaries in Transparent Polycrystalline Ce3+-Doped (Gd,Y)3Al5O12Garnet 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)3Al5O12disordered 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)3Al5O12ceramic. A strong Ce3+segregation and spatial distribution between grains and grain boundaries were observed.