Abstract
EXAFS and confocal Raman microscopy have been used to study 50SnF2.(20-x)SnO.30P2O5.xEr2O3 (x=0, 0.1, 0.25) glasses. EXAFS data reveal an average coordination of Sn to O of 1.5 in both undoped glass and Er-doped glass samples. The first coordination sphere of Er in glasses doped with Er2O3 was found to have 9 F atom neighbours at an average bond length of 2.292±0.005 Å, indicating that Er preferentially bonds with F. Raman spectra clearly show the emergence of orthophosphate Q0 units on addition of Er2O3. The saturation of Er solubility is found to be between 0.25 and 0.5 mol% Er2O3. An increase of the glass transition temperature from ∼80°C in undoped glass to ∼87°C in samples doped with 0.25 mol% Er2O3 was also observed. This process is accompanied by an increase in the difference between the crystallisation and glass transition temperatures, which is usually associated with improved thermal stability of the glass.
| Original language | English |
|---|---|
| Pages (from-to) | 27-31 |
| Number of pages | 5 |
| Journal | Physics and Chemistry of Glasses: European Journal of Glass Science and Technology Part B |
| Volume | 57 |
| Issue number | 1 |
| DOIs | |
| State | Published - Feb 2016 |
| Externally published | Yes |
Funding
We would like to thank the NSF International Materials Institute for New Functionality in Glass (NSF Grant No. DMR 0844014) and the NASA Tennessee Space Grant Consortium for funding. The Horiba Fluorolog 3 and Horiba Confocal Raman Microscope were purchased under NASA grant/cooperative agreement NNX10AJ04G. EXAFS data were taken at the X18B NSLS beamline at Brookhaven National Laboratory. The scientific and technical support of Dr. Syed Khalid (NSLS), and Chatree Saiyasombat (Lehigh University) are highly appreciated. The authors would like also to acknowledge the intellectual contribution of former undergraduate students at Austin Peay State University: Nichole Boyer, Tristan Harper and James York-Winegar.