Optical, physical and structural studies of vanadium doped P 2O5-BaO-Li2O glasses

Glasses in the compositions (Li2O)25–(BaO)25–(P2O5)50−x–(V2O5)x (with x=0.5,1.0,1.5,2.0,2.5, and 3.0 mol%) have been prepared by the conventional melt quenching technique. X-ray powder diffractrogram show broad peaks which conforms glassy nature of the sample. Differential scanning calorimetry (DSC) thermograms show characteristic glass transition temperature (Tg) and it increases with increasing substitution of V2O5 for P2O5. The measured physical parameters like density, refractive index, ionic concentration and electronic polarizability are found to vary linearly with increasing x. Infrared spectra exhibits few bands, which are attributed to (P=O)AS, (P=O)S, (V=O), (P–O–P)AS,P–O–V, (P–O–P)AS and O–P–O vibrations. The optical absorption spectra of VO2+ ions in these glasses show three bands and are assigned to the 2B2→ 2E,2B2→ 2B1 and 2B2→ 2A1 transitions. Electron paramagnetic resonance spectra of all the glass samples exhibit resonance signals characteristic of VO2+ ions. The values of Spin-Hamiltonian parameters indicate that the VO2+ ions are present in octahedral sites with tetragonal compression and belong to C4V symmetry

Characterization and structural studies of lithium doped lead zinc phosphate glass system

Glasses in the system (PbO) 30(P 2O 5) 40(ZnO) 30-x(Li 2O) x (where x = 0, 15, 20, 25, 30 mol) and (PbO) 30(P 2O 5) 50(ZnO) 20-x(Li 2O) x (where x = 0, 5, 10, 15, 20 mol) were prepared by conventional melt quenching technique. XRD and DSC measurements were performed to confirm their amorphous nature. Thermal stability factor (S) has been evaluated using the values of T g and T c. The refractive indices of these glasses lie in the range of 1.40-1.45. IR spectra of these glasses show absorption peaks in the range 1233-1247 cm -1, 1076-1087 cm -1, 905-894 cm -1, 735-731 cm -1 and 531-556 cm -1 corresponding to PO, PO -, (POP) AS, (POP) S and OPO vibrations respectively. The peak corresponding to PO, shows red shift with increasing Li 2O content indicating depolymerization of phosphate network. © 2012 Elsevier B.V

Optical properties and Judd-Ofelt analysis of Nd[sup 3+] ions in lead-zinc-phosphate glasses

Nd3+ doped lead zinc phosphate glasses with the chemical composition 30PbO-30ZnO-(40−x)P2O5−xNd2O3 (where x = 0.5,1,1.5 and 2 mol%) have been prepared by conventional melt quenching technique. Spectroscopic properties of these glasses have been studied by recording the optical absorption in the UV-Visible range 300-900nm. The Judd-Ofelt (JO) analysis have been carried out to determine JO intensity parameters Ωλ (λ = 2, 4, and 6). It is observed that Ω2>Ω6>Ω4 . A large value of Ω2 indicates the presence of covalent bonding between the Nd3+ ions and the surrounding ligands. The values of oscillator strength calculated experimentally and theoretically agree well

Characterization and optical properties of Pr2O3-doped molybdenum lead-borate glasses

Pr3+ doped molybdenum lead-borate glasses with the chemical composition 75PbO-25-(x+y)B2O3-yMoO3-xPr2O3 (where x = 0.5 and 1.0 mol% and y = 0 and 5 mol%) were prepared by conventional melt-quenching technique. Thermal, optical and structural analyses are carried out using DSC, UV and FTIR spectra. The physical parameters, like glass transition (Tg), stability factor (�T), optical energy band gap (Egopt), of these glasses have been determined as a function of dopant concentration. The Tg and optical energy gaps of these glasses were found to be in the range of 290-350°C and 2.45-2.7 eV, respectively. Stability of the glass doped with Pr3+ is found to be moderate (�40). The results are discussed using the structural model of Mo.lead-borate glass. © Indian Academy of Sciences

Transport properties of PbO-P2O5-ZnO-Li2O glass system

The electrical conductivity of Li+ ion conducting lead zinc phosphate glasses have been carried out both as a function of temperature and frequency in the temperature range 458-510K and over frequencies 40 Hz to 10 MHz. The dc conductivities show Arrhenius behavior and show compositional dependence. The Ï decreases with increase in Li2O content. The ac conductivity behavior has been analyzed using Almond-West power law using a single exponent. The exponent 's' obtained from the power law fits is found to have values ranging from 0.74 - 0.80 in these glasses and shows moderate temperature dependence, which is attributed to high degree of modification in the glass network. © 2012 American Institute of Physics

Li+ ion transport studies in Li2O-Li 2SO4-ZnO-B2O3 glass system

Li+ ion transport studies have been carried in Li 2O-Li2SO4-ZnO-B2O3 glass system. Electrical conductivity has been measured out over a wide range of temperature (450K-500K) and frequencies (40 Hz - 10 MHz). The dc conductivities show Arrhenius behavior and show compositional dependence. The ac conductivity behavior has been analyzed using Almond-West power law using a single exponent. The exponent 's' obtained from the power law fits is found to have values ranging from 0.36-0.45 in these glasses and shows temperature dependence, which is attributed to high degree of modification in the glass network. © 2013 AIP Publishing LLC

Optical properties of Pb0-ZnO-P2O5 glasses doped with samarium and neodymium

(PbO) 30(ZnO) 20(P 2O 5) 50-x(Nd 2O 3) x and (PbO) 30(ZnO) 20(P 2O 5) 50-x(Sm 2O 3) x glasses (where x=0.5, 1, 2%) have been prepared by conventional melt quenching method. Measurements of X-ray diffractrogram reveal samples prepared are amorphous in nature, DSC studies have been made and the glass transition temperature (T g), crystallization temperature (T c) and glass stability factor have been evaluated. These glasses exhibit high transition temperature (T g) and high stability factor (S) indicating glasses are stable. IR spectra of these glasses show absorption peaks at 1215cm -1, 1072cm -1 and 728cm -1 corresponding to P=O, P-O-P and P-O - vibrations. Optical absorption studies show absorption peaks in the range of 462.5-584 nm for various transition in the Nd 3+ ion and 287.5-562.5 nm in case Sm 3+. © 2011 American Institute of Physics

Characterization and structural studies of vanadium doped lithium-barium-phosphate glasses

Characterization and structural studies of (P 2O 5) 49.5(V 2O 5) 0.5(BaO) x(Li 2O) 50-x (where x = 0, 5, 10, 15, 20, 25 mol) glasses are reported. These glasses were prepared using the conventional melt quenching technique. X-ray diffraction and differential scanning calorimetry measurements were performed to confirm their amorphous nature. Infrared spectra of these glasses show absorption peaks in the ranges 1273-1267; 1098-1088; 1008-1018; 899-889; and 795-760 and 506-474 cm -1 corresponding to P=O, P-O -, (P-O-P) S, (P-O-P) AS, and O-P-O group vibrations, respectively. Thermal stability factor (s) has been evaluated using the values of T g and T c. These glasses exhibit high transition temperature (T g) and high thermal stability factor (s) indicating that they are thermally stable. Refractive index of the glasses lies in the range 1.59-1.49. Electron paramagnetic resonance spectroscopy of V 4+ show characteristic hyperfine split signal arising from the vanadyl group in this glass matrix. The results are discussed by considering the structural modification of the phosphate network. © 2012 Published by NRC Research Press

Transport properties of phospho-vanadate glasses containing bismuth

Phospho-vanadate glasses containing various compositions of bismuth oxide were synthesized by melt quenching technique. Electrical conductivity has been measured over a wide range of temperature (373K-480K) and frequency (40 Hz -10 MHz) range. The data have been analyzed in the light of polaronic hopping model. The total conductivity at all the frequencies is due to both polarons and Bi2O3. It is seen that the conductivity increases with Bi2O3 content indicating that there is ionic contribution to the total conductivity in addition to electronic. The exponent ‘s’ obtained from the power law in these glasses shows temperature dependence, which is attributed to high degree of modification in the glass network

Optical, structural and Near-IR NLO properties of gold nanoparticles doped sodium zinc borate glasses

Gold (Au) nanoparticles (NP) embedded borate glasses with the molar composition of (x‒0.1)Na2O‒10ZnO‒(90‒x)B2O3‒0.1AuCl3 (x = 10, 20, 30 mol %) have been prepared via melt quench technique. The effect of Na2O content on properties such as optical, structural and nonlinear optical (NLO) properties of gold NPs containing sodium zinc borate glasses were studied using UV‒Visible absorption, Fourier Transform Infrared spectroscopy (FTIR), High Resolution-Transmission Electron Microscope (HR‒TEM) and Z-scan measurements. X‒ray diffraction (XRD) measurements confirmed the glassy nature of the samples. UV‒Visible absorption spectra of glasses comprising Au NPs demonstrated a broad surface plasmon resonance (SPR) absorption peak near 577 nm due to the transition from d‒band to the Fermi level and this SPR peak demonstrated a red‒shift with increase in Na2O concentration. HR‒TEM micrographs revealed the presence of uniformly distributed and spherical shaped Au nanoparticles with an estimated average particle size of ∼6 nm (±1.5 nm). Nonlinear Optical (NLO) measurements were performed at three different off‒resonant wavelengths (750 nm, 800 nm, 850 nm) using femtosecond (fs) pulses (150 fs, 80 MHz) delivered by aTi:sapphire oscillator. Saturable Absorption (SA) kind of nonlinearity has been observed in the open aperture (OA) Z-scan data and is attributed to intraband transition within the Au NPs, while the closed aperture (CA) Z-scan data illustrated a negative type of nonlinear refraction attributed to effect of self-defocusing. NLO studies and the obtained nonlinear coefficients suggest that, the NZB glasses are potential candidates for mode-locking and switching applications in near-infrared spectral region. © 2018 Elsevier B.V