Inder Pal

Spectroscopic properties of Sm3+ doped lead bismosilicate glasses using Judd–Ofelt theory

The spectroscopic properties of Sm(3+) ions in lead bismosilicate glasses (PBSS) as a function of bismuth oxide were investigated using optical absorption and fluorescence spectra. These glasses have shown strong absorption and emission bands in the near infrared and visible region respectively. From the measured absorption spectra, Judd-Ofelt intensity parameters Ω2, Ω4 and Ω6 were determined by applying least square analysis method. The variation of Ω2 and Ω6 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth ion site and to the changes in the rare earth oxygen (RE-O) covalency. The variation of Ω4 with Bi2O3 content has been attributed to rigidity of the samples. Using the Judd Ofelt intensity parameters the other radiative properties like radiative transition probability, radiative life time, branching ratio and the stimulated emission cross-sections of prepared PBSS glasses have been calculated. The values of radiative properties indicate that Sm(3+) ions emit intense reddish-orange emission ((4)G5/2→(6)H7/2) under excitation at 450 nm wavelength.

Investigation of spectroscopic properties, structure and luminescence spectra of Sm3+ doped zinc bismuth silicate glasses

The glasses with compositions 20ZnO·(79.5-x)Bi2O3·xSiO2·0.5Sm2O3 (10≤x≤50, mol%) have been synthesized using normal melt-quench technique. Optical absorption and fluorescence spectra of the glasses were recorded at ambient temperature. Judd-Ofelt (J-O) theory has been successfully applied to characterize the absorption and luminescence spectra of these glasses. From the measured intensities of absorption bands of these glasses, the Judd-Ofelt parameters, Ωλ (λ=2, 4, 6) have been evaluated. The variation of Ω2 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth (RE) ion site (due to structural change) and to changes in RE-O covalency, whereas the variation of Ω6 is found to be strongly dependent on nephlauxetic effect. The shift of the hypersensitive band shows that the covalency of the RE-O decreases with decrease in Bi2O3 content in the host glass. Also, using J-O theory various radiative properties like spontaneous emission probability (Arad), radiative life time (τr), fluorescence branching ratio (βr) and stimulated emission cross-section (σ) for various emission bands of these glasses in the visible spectral region have been determined. A close correlation is observed between the Bi2O3 content and the spectroscopic, radiative and structural properties of the prepared glasses. The values of radiative properties indicated that 4G5/2→6H7/2 and 4G5/2→6H9/2 transitions responsible for orange luminescence might be used in the development of materials for LEDs and other optical devices in the visible region.

Effect of Bi2O3 on spectroscopic and structural properties of Er3+ doped cadmium bismuth borate glasses

Glasses with composition 20CdO·xBi(2)O(3)·(79.5-x)B(2)O(3) (15≤x≤35, x in mol%) containing 0.5 mol% of Er(3+) ions were prepared by melt-quench technique (1150°C in air). The amorphous nature of the glasses was confirmed by X-ray diffraction. The spectroscopic properties of the glasses were investigated using optical absorption spectra and fluorescence spectra. The phenomenological Judd-Ofelt intensity parameters Ω(λ) (λ=2, 4, 6) were determined from the spectral intensities of absorption bands in order to calculate the radiative transition probability (A(R)), radiative life time (τ(R)), branching ratios (β(R)) for various excited luminescent states. Using the near infrared emission spectra, full width at half maxima (FWHM), stimulated emission cross-section (σ(e)) and figure of merit (FOM) were evaluated and compared with other hosts. Especially, the numerical values of these parameters indicate that the emission transition (4)I(13/2)→(4)I(15/2) at 1.506 μm in Er(3+)-doped cadmium bismuth borate glasses may be useful in optical communication.

OPTICAL ABSORPTION AND STRUCTURAL STUDIES OF Pr3+ DOPED CADMIUM BISMUTH BORATE GLASSES IN VISIBLE AND NEAR INFRARED REGIONS

Glasses having composition 20CdOxBi2O3(79.5-x)B2O30.5Pr6O11 with x varying from 15 to 35 mol% have been synthesized. Optical absorption and fluorescence spectra were measured at ambient temperature. A close correlation is observed between the Bi2O3 content and the spectroscopic properties such as Judd-Ofelt intensity parameters Ωλ = (λ = 2, 4, 6), radiative and structural properties of prepared glasses doped with Pr3+ ion. The variation of Ω2 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth (RE) ion site (due to structural change) and to changes in RE-O covalency, whereas the variation of Ω6 has been related to the variation in RE-O covalency. Following the luminescence spectra, various radiative properties like transition probability (Arad), radiative lifetime (τr), branching ratio (βr) and stimulated emission cross section (σ) have been calculated. The branching ratio for 3P0 → 3F2 transition of Pr3+ glass system arrive at 41 to 40%, respectively, and the predicted spontaneous radiative transition probability rates are high and varies from 14032 to 14864 s−1. In addition, the glass stability is improved in which the substitution of B2O3 for Bi2O3 strengthens the glass network structure. The bismuth based glass as a host for Pr3+ ion doped suggesting their suitability for laser applications.

Current Trends on Glass and Ceramic Materials

Description: Biomaterials created from innovative glass and bio-ceramic research is emerging as a precursor to several developments useful for solving a wide variety of industry and health related issues. Current Trends on Glass and Ceramic Materials is a review on the latest developments in glass and ceramic materials for technological applications along with biomedical applications in vivo. The volume serves as a useful reference to readers interested in learning about this area of materials science and its multidisciplinary array of applications.

SPECTROSCOPIC PROPERTIES OF ERBIUM IONS DOPED IN BISMUTH BORO-SILICATE GLASSES

Glasses with composition 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) containing 0.5mol% of Er3+ ions were prepared by melt-quench technique. Optical absorption and fluorescence spectra were recorded at room temperature for all glass samples. Based on the Judd-Offelt theory, spectroscopic properties of Er3+ ions are discussed by changing the host glass compositions. The intensity parameters Ω2, Ω4, and Ω6 are determined by applying least square analysis method. The variation of Ω2 and Ω6 with Bi2O3 content has been attributed to changes in the asymmetry of the ligand field at the rare earth ion site and to the changes in the rare earth oxygen (RE-O) covalency. The variation of Ω4 with Bi2O3 content has been attributed to rigidity of the samples. Using these intensity parameters various radiative properties like spontaneous emission probability, branching ratio, radiative life time and stimulated emission cross-section of various emission lines have been evaluated. An intense green luminescence bands with maximum around 516 nm and 536 nm are assigned to the 2H11/2→ 4I15/2 and 4S3/2→ 4I15/2 transitions respectively has been obtained.

Absorbance and Fluorescence Spectral Analysis of Sm3+ Ions Doped Bismuth Boro-Silicate Glasses

Glasses having compositions 20B2O3.(79.5-x)Bi2O3.xSiO2 (10 ≤ x ≤ 40) doped with 0.5 mol% of Sm 3+ ions were prepared by melt quench technique. The amorphous nature of the glasses was confirmed by X-ray diffraction studies. The spectroscopic properties of Sm 3+ ions in bismuth borosilicate glasses as a function of bismuth oxide were investigated using optical absorption and fluorescence spectra. The Judd-Ofelt theory has been employed to calculate transitions probability from the data of absorption cross-section of several f-f transitions. The intensity parameters Ω2 is related to the symmetry of glass hosts, where as the parameter Ω6 is inversely proportional to the rare earth oxygen (RE-O) covalency. The variation of Ω4 with Bi2O3 content has been attributed to rigidity of the samples. Using the Judd Ofelt intensity parameters the other radiative properties like radiative transition probability, radiative life time, branching ratio and the stimulated emission cross-sections of prepared BBSS glasses have been calculated. A bright fluorescent orange emission at 600 nm (4 G 5/2 → 6 H 7/2) of Sm 3+ ion has been investigated as a function of Bi2O3 in host glass. The radiative transition probabilities of Sm 3+ ions are large in bismuth borosilicate glasses, suggesting the suitability of these glasses as potential candidate for laser application.