Microstructure and spectroscopic investigations of calcium zinc bismuth phosphate glass ceramics doped with manganese ions

作者：Kumar A Suneel; Rao M V Sambasiva; Ram G Chinna; Rao D Krishna^*

来源：Indian Journal of Physics and Proceedings of the Indian Association for the Cultivation of Science, 2018, 92(1): 97-109.

DOI：10.1007/s12648-017-1069-0

• Calcium zinc bismuth phosphate glass ceramics
• EPR
• Crystallization
• Raman and optical spectroscopy
• Delocalization process
• Insulators
• SEM
• X-ray diffraction
• Infrared spectra

Multi-component 10CaF(2)-20ZnO-(15 - x)Bi2O3-55P(2)O(5):xMnO (0 <= x <= 2.5) glass ceramics were synthesised by melt quenching technique and heat treatment. The prepared glass ceramics were characterised by XRD, DTA, EDS and SEM. Spectroscopic studies such as optical absorption, EPR, FTIR and Raman were also carried out on these glass ceramics. The XRD and SEM studies have indicated that ceramic samples contain well defined and randomly distributed grains of different crystalline phases. The observed increase of enthalpy from DTA patterns up to 1 mol% of MnO indicates that the crystallisation starts initially from the surface of the material then gradually it is extended to the volume of the material and this influence is meagre at higher concentrations of MnO. The absorption spectra of manganese doped glass ceramics have exhibited two types of conventional bands; one due to Mn2+ ions and other due to Mn3+ ions. The EPR spectra of MnO doped glass ceramics showed a resonance signal around g(2) = 2.023 with a six line hyperfine structure and another signal at about g(1) = 4.314. The relative intensity and half-width of these two signals are observed to increase with the increase in the concentration of manganese ions up to 1 mol% beyond this concentration it is found to decrease. Such observation indicates the conversion of part of Mn2+ ions into Mn3+ ions in the glass ceramic matrix. The observed increase in the intensity of symmetrical structural units at the expense of asymmetrical structural units from the FTIR and Raman spectra at higher concentration of MnO indicating that Mn2+ ions occupy the network forming positions in the glass ceramic structure.

• 出版日期2018-1