Reduction effects on divalent and trivalent europium ions in CaF2 nano particles investigated by optical and luminescence spectroscopy

Jang, Kyoung-Hyuk (Department of Physics, Pukyong National University) ;
Kim, Eun-Sik (Department of Physics, Pukyong National University) ;
Kim, Kyung-Hyang (Department of Physics, Pukyong National University) ;
Shi, Liang (Department of Physics, Pukyong National University) ;
Seo, Hyo-Jin (Department of Physics, Pukyong National University) ;
Hong, Byung-Chul (Department of Electronic Engineering, The University of Electro-Communications) ;
Kawano, Katsuyasu (Department of Electronic Engineering, The University of Electro-Communications) ;
Tsuboi, Taiju (Faculty of Engineering, Kyoto Sangyo University)