Hydrothermal synthesis of Yb
3+
, Tm
3+
co-doped Gd
6
MoO
12
and its upconversion properties
*
Di Qiu-Mei, Sun Yu-Mei, Xu Qi-Guang, Han Liu, Xue Bing, Sun Jia-Yue†
Schematic energy levels of Yb
3+
and Tm
3+
ions in the as-prepared Gd
6
MoO
12
:Yb
3+
/Tm
3+
sample.