Structural and optical absorption studies on Cr₂O₃ doped SrO-P₂O₅ glasses

Area of Science:

• Materials Science
• Solid State Chemistry
• Glass Science

Background:

• Chromium oxide (Cr2O3) doping is explored in strontium phosphate glass systems.
• Understanding the structural and optical properties of doped glasses is crucial for material applications.

Purpose of the Study:

• To synthesize and characterize Cr2O3 doped strontium phosphate glasses.
• To investigate the effect of varying Cr2O3 concentrations on the structural and optical properties of the glass network.

Main Methods:

• Glass samples were prepared using varying concentrations of Cr2O3.
• X-ray diffraction (XRD) was used to confirm the amorphous nature of the samples.
• UV-Visible (UV-Vis) spectroscopy was employed to study optical absorption and energy gaps.
• Fourier Transform Infrared (FTIR) spectroscopy analyzed structural changes.

Main Results:

• X-ray data confirmed the amorphous structure of all prepared glass samples.
• UV-Vis spectroscopy revealed the presence of both trivalent and hexavalent chromium ions.
• An increase in Cr2O3 concentration led to a decrease in both direct and indirect optical energy gaps (from 4.92 to 4.4 eV and 3.94 to 3.5 eV, respectively).
• FTIR spectra showed minor differences in doped glasses compared to the base glass, suggesting Cr2O3 acts as a network former.

Conclusions:

• The addition of Cr2O3 influences the optical properties of strontium phosphate glasses, primarily by reducing the optical energy gap.
• The observed changes are attributed to the network-forming capability of Cr2O3 and the presence of chromium in multiple oxidation states.
• Physical and optical parameters showed similarity to the base glass, likely due to the low doping concentrations used.