Browsing by Author "Laxmikanth, C."

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    Dosimetric and kinetic parameters of lithium cadmium borate glasses doped with rare earth ions
    (Elsevier, 2014) Anjaiah, J.; Laxmikanth, C.; Kistaiah, P.; Veeraiah, N.
    Thermoluminescence (TL) characteristics of X-ray irradiated pure and doped with four different rare earth ions (viz., Pr3þ, Nd3þ, Sm3þ and Eu3þ) Li2OeCdoeB2O3 glasses have been studied in the temperature range 303e573 K; the pure glass has exhibited single TL peak at 466 K. When this glass is doped with different rare earth ions no additional peaks are observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve is found to be maximum for Eu3þ doped glasses. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen's formulae. The possible use of these glasses in radiation dosimetry has been described. The result clearly showed that europium doped cadmium borate glass has a potential to be considered as the thermoluminescence dosimeter
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    Influence of rare-earth ion doping on dielectric properties of lithium zinc borate glasses
    (Elsevier, 2022) Anjaiah, J.; Laxmikanth, C.; Mwanga, Stanley Ferdinand; Raju, P.; Shankar, J.; Rani, G. Neeraja; Mwankemwa, Benard; Ali, S, K. M.
    The dielectric constant (ε′), loss factor (tanδ), and ac conductivity (σac) of 30 Li2O-10 ZnO-(60-x) B2O3: xLn2O3, where (x = 0 and 1) and (Ln = Pr, Nd, Sm, and Eu) were investigated using a frequency range of 102–105 Hz and temperature ranging from 30 to 250 °C in this work. Differential Scanning Calorimetry (DSC) technique was employed to confirm the glassy nature of the materials under study. The dielectric parameters ε′, tanδ, and σac rise when rare-earth ions are added to the glass matrix at any frequency or temperature. Dielectric breakdown and activation energies are lower in doped than in undoped glasses while ac current flows through them at room temperature. Rare-earth ion doping's dielectric parameter values decrease with temperature as atomic number (Z) rises. The dielectric parameter values for the Pr3+ doped glass matrix are the highest. QM tunnelling model was used to describe the ac conduction behaviour of these glasses.
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    Luminescence and spectroscopic properties of ZnF2–MO–TeO2 glasses doped with Ho3+ ions
    (Elsevier, 2015) Laxmikanth, C.; Anjaiah, J.; Rao, P. V.; Veeraiah, N.
    ZnF2–TeO2 glasses mixed with the three different modifier oxides (MO) viz., ZnO, CdO and PbO doped with Ho2O3 were prepared. These glasses were characterized by X-ray diffraction, and IR spectra. Optical absorption and fluorescence spectra of these glasses have been studied. From the measured intensities of various absorption bands of these glasses the Judd–Ofelt parameters Xk (k = 2, 4, 6) have been evaluated and compared with those of other reported glass systems. From the Judd–Ofelt theory various radiative properties like transition probability A, branching ratio bR, the radiative life time sR, and the emission cross-section rP for various emission levels of these glasses have been determined and reported.
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    Spectroscopic properties and luminescence behaviour of europium doped lithium borate glasses
    (Elsevier, 2014) Anjaiah, J.; Laxmikanth, C.; Veeraiah, N.
    Li2O–MO–B2O3 (MO=ZnO, CaO and CdO) glasses doped with europium are prepared by using the melt quenching technique to study their absorption and luminescence properties to understand their lasing potentialities. The XRD pattern of the glasses confirmed the amorphous nature and the IR spectra reveal the presence of BO3 and BO4 units in the glass network. Judd–Ofelt intensity parameters (λ=2, 4, 6) are evaluated from the intensities of various absorption bands of optical absorption spectra. The J–O parameters have been used to calculate transition probabilities (A), lifetime (TR), branching ratios (βR) and stimulated emission cross-section (σρ) for the 5D0→7FJ (J=1–4) transitions of the Eu3+ ions. The decay from the 5D0 level of Eu3+ ions in these glasses has been measured and analysed. Branching ratios and stimulated emission cross-sections measured for all these glasses show that the 5D0→7F1 transition under investigation has the potential for laser applications. The high stimulated emission cross-section and branching ratios from the present glasses suggests their potential for infra-red lasers. The study of the thermoluminescence is also carried out and the data suggests that the CdBEu glass is suitable for thermoluminescence emission output among the three Eu3+ doped glasses.
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    Spectroscopic studies of titanium ions in PbO–Sb2O3–As2O3 glass system
    (Elsevier, 2004) Laxmikanth, C.; Veeraiah, N.; Raghavaiah, B, V.
    PbO–Sb2O3–As2O3 glasses containing small concentrations of TiO2 ranging from 0 to 0.5 mol% were prepared. A number of studies viz. differential scanning calorimetry, infrared spectra, optical absorption, ESR spectra and magnetic susceptibility have been carried out as a function of titanium ion concentration. The interesting changes observed in these properties are discussed in the light of different oxidation states of titanium ions.