Date of this Version
Materials Chemistry and Physics 147 (2014)
Using extended X-ray absorption fine structure (EXAFS) spectroscopy, we find that Cr substitutes primarily in the Liþ site as a dopant in lithium tetraborate Li2B4O7 glasses, in this case 98.4Li2B4O7e1.6Cr2O3 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.