| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1521823 | Materials Chemistry and Physics | 2014 | 4 Pages |
•Adoption of the Li + site for chromium dopants in lithium tetraborate identified.•Increased oxygen coordination for glass over the crystalline lithium tetraborate.•Distortions about the doping chromium characterized.•Local bond order is preserved in spite of the glassy nature.
Using extended X-ray absorption fine structure (EXAFS) spectroscopy, we find that Cr substitutes primarily in the Li+ site as a dopant in lithium tetraborate Li2B4O7 glasses, in this case 98.4Li2B4O7–1.6Cr2O3 or nominally Li1.98Cr0.025B4O7. This strong preference for a single site is nonetheless accompanied by site distortions and some site disorder, helping explain the optical properties of chromium doped Li2B4O7 glasses. The resulting O coordination shell has a contraction of the Cr–O bond lengths as compared to the Li–O bond lengths. There is also an increase in the O coordination number.
Graphical abstractLithium tetraborate: labeled are the B1 and B2 sites, where the latter correspond to BO3 and BO4 structures respectively.Figure optionsDownload full-size imageDownload as PowerPoint slide
