Control of Grain Boundaries and Defects in Nano-Engineered Transparent Scintillator Ceramics
Abstract
This research program focused mainly on the relationship between macro-scale defects on the scintillator properties of optical ceramics. The former includes grain boundaries, porosity and solid phase inclusions, and the latter, lattice imperfections. The following important results were found: 1) Oxygen defects in hot pressed Eu-doped yttrium oxide ceramics dwarf the influence of grain boundary defects on scintillator light yield (5 to 250 micron grain size range). A direct relationship was found between the in-diffusion of oxygen during annealing and the decrease in the number of charge carrier traps. This oxygen up-take resulted in an increased in light yield. 2) Two novel micro-scale scintillation characterization techniques were developed. 3) Grain boundary recombination is Eu-doped yttrium oxide ceramics (grain sizes>~30 microns) was found to be minimal. Transmission electron microscopy showed that these ceramics had abrupt boundaries, 4) In vacuum sintered Ce-doped yttrium aluminum garnet ceramics, a relationship was found between cation non-stoichiometry, anti-site defects, and light yield. 5) in translucent Eu-doped strontium iodide ceramics produced by hot pressing, a relationship between transparency, grain texture and scintillation properties was identified.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2013
- Accession Number
- ADA578956
Entities
People
- R. Gaume
- Robert S. Feigelson
- S. R. Podowitz
Organizations
- Stanford University