TY  - JOUR 
T1  - Optical properties of ZrO2, SiO2 and TiO2-SiO2 xerogels and coatings doped with Eu3+ and Eu2+
JO  - Materials Research
A1  - Gonçalves, Rogéria R.
A1  - Messaddeq, Younes
A1  - Atik, Mohamed
A1  - Ribeiro, Sidney J.L.
SN  - 1516-1439
UL  - 10.1590/S1516-14391999000100003
VL  - 2 
Y1  - 1999
PB  - Brasil 
ER  -