Author/Authors :
Cui، نويسنده , , Yunlong and Hawrami، نويسنده , , R. and Tupitysn، نويسنده , , Eugen and Bhattacharya، نويسنده , , Pijush and Groza، نويسنده , , Mike and Bryant، نويسنده , , Mark and Buliga، نويسنده , , Vladimir and Bürger، نويسنده , , Arnold and Cherepy، نويسنده , , Nerine J. and Payne، نويسنده , , S.A.، نويسنده ,
Abstract :
Europium-doped barium and strontium iodide crystals are high light yield scintillator materials with excellent energy resolution. In this communication, BaI2:Eu and SrI2:Eu single crystals with space groups of Pnma ( D 2 h 16 ) and Pbca ( D 2 h 15 ) respectively were grown from the vertical Bridgman method. The crystals were investigated with polarized Raman spectroscopy at temperatures varied from 77 to 300 K. The observed Raman-active modes for each crystal were assigned with the help of group theory analysis. It is found that the absence of the site symmetry leads to splitting of a spectral line in Pnma structure into two lines in the Pbca structure. Structural defects including dark spots formed during crystal growth and new species produced from hydration were characterized.
