Characterization of Cr3+ doped zinc lead lithium phosphate glasses

Abstract

Cr3+ metal ion doped Zinc-Lead-Lithium-Phosphate glass samples are made by melt quenching technique, by varying 0.2% mol (20-x) Li2CO3−x Cr2O3 in glass mixture composition. To identify basic structural units in these glasses, to investigate structural changes with the change in glass composition and to relate structural changes with the difference in properties of glasses, the samples subjected to spectral studies of XRD, UV–vis, EPR and FTIR. The physical properties of the glass samples like average molecular weight, Cr3+ ion concentration, density, refractive index etc, were calculated. Spin–Hamiltonian parameters are evaluated from EPR spectra which exhibit two resonance intense signals representing coupled pair and free state of Cr3+ ions. The breakage of Phosphorous—Oxygen—Phosphorous (P–O–P) link and the development of cross ionic bonding among the chains of phosphate are identified in FTIR spectra. From optical absorption spectra, crystal field parameters and optical band gap values have been calculated. The optical band gap value of the prepared phosphate glasses is found to lie in the range 1.60–1.63 eV, which fined immediate applications in the fabrication of ultra high speed Integrated circuits, IR photon detectors and thin films.