Table 4.

Thermal parameters of undoped and 1 mol% rare earth-doped zinc cadmium phosphate glasses annealed at 320 °C and 650 °C.

Sample code	Tg (°C)	Td (°C)	CTE (10–6/°C)
Undoped glass at 320 °C	302	330	7.60
1% Er2O3 glass at 320 °C	319	347	7.09
1% Tb2O3 glass at 320 °C	311	343	4.60
Undoped glass at 650 °C	373	401	5.61
1% Er2O3 glass at 650 °C	392	422	2.40
1% Tb2O3 glass at 650 °C	412	440	3.40