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Tri-positive lanthanide ion (Eu3+) activated glasses doped with different concentrations of silver (Ag0) nanoparticles obtained using thermal reducing agent were fabricated by applying the method of melt quench. The formation of Ag0 nanoparticles in glasses was revealed by the surface plasmon resonance (SPR) peak in the absorption spectra. Transmission electron microscopic measurements confirmed the presence of spherically shaped Ag0 nanoparticles of different size distribution. The absorption spectra showed a red–shift of the SPR peak with an increase in AgNO3 concentration occurring through Ostwald's ripening process because of the growth of particle size (as evidenced from microscope images). The non-linear optical (NLO) and optical limiting measurements were performed in the near infrared spectral region and femtosecond pulse excitation. The non-linear parameters were found to increase as the AgNO3 concentration increased to 0.6 mol %, however, the parameters subsequently decreased at higher doping level. The optical limiting threshold values demonstrated a reverse trend. The increase in non-linear optical properties regarding Ag nanoparticles concentration attributed to the enhancement of polarizabilities of glasses that occurred through local field stimulated by SPR of Ag nanoparticles when exposed to laser radiation of high energy. The increase in NLO coefficients (particularly the non-linear absorption coefficient) and the decrease in optical limiting threshold values with AgNO3 concentration (up to 0.6 mol %) indicated that these glasses containing 0.6 mol % AgNO3 are useful for the construction of the power optical limiters that function at the infrared region in the femtosecond pulse regime.

In this work, multi wall carbon nanotube (MWCNT) doped borate glass has been successfully developed by melt quenching technique with the chemical composition 67.5B2O3-20ZnO-12Gd2O3-Er2O3-0.5MWCNT. ...

The Dy2O3 doped phosphate glasses of chemical composition 10ZnO · 10BaO · 10Gd2O3 · 70P2O5, 10ZnO · 10BaO · 10Gd2O3 · 69P2O5 · 1Dy2O3 and 10ZnO · 10BaO · 10GdF3 · 69P2O5 · 1Dy2O3 were prepared by melt quench technique. The prepared glass samples were characterized through physical and luminescence properties such as density, molar volume, refractive index, FTIR, UV-Vis-NIR absorption spectra, photoluminescence excitation and emissions, radio-luminescence and life time. The J–O theory were analyzed to calculate the radiative properties such as radiative transition probabilities (AR), stimulated emission cross section (σR) and branching ratio (βR). Total nine characteristics absorption peaks belong to Dy3+ ion at the 347, 386, 454, 750, 800, 896, 1089 and1674 nm respectively corresponding to transition from ground state 6H15/2 to excited state 4M15/2+4I15/2, 4F7/2+4I13/2, 4I15/2, 6F3/2, 6F5/2, 6F7/2, 6F9/2 and 6H11/2 are observed in absorption spectra in the 300–1900 nm region. The photoluminescence and radio-luminescence emission spectra of the present glasses were recorded and found in good agreement with one another. The CIE 1931 chromaticity color coordinates were evaluated and it is found that these coordinates positioned in the white region with (x, y) = (0.39, 0.44) values for both oxide and oxyfluoride glasses. The florescence decay time from 4F9/2 level was measured by monitoring the intense 4F9/2 → 6H13/2 (573 nm) transition. The decay time is found to be non-exponential so the non-exponential curve was well fitted to Inokuti–Hirayama (IH) model for S = 6. The results obtained in present work demonstrate that the present glasses could be a good choice for use in white light solid state lighting applications.

The Co1 − (x + y)MgxNiyCr2O4(where, x = y = 0.00, 0.05) nanoparticles were synthesized by the solution combustion technique using a mixture of carbamide and glucose as fuel. The refined XRD study confirmed that samples are single-phased with spinel cubic structure having space group Fd3m. The difference in ionic radius of Co2+ ions and Mg2+, Ni2+ ions resulted in the reduction in lattice parameters. The stretching vibration modes are found at tetrahedral and octahedral site by using FTIR spectra. Force constant value also estimated from FTIR spectra. The magnetic transition was studied by using temperature-dependent magnetization. The magnetic transitions such as ferrimagnetism transition were observed at Curie temperature (TC = 98 K, 91 K for x = y = 0.00, 0.05, respectively), and spiral spin transition was observed at spiral temperature (TS = 26 K, 17 K for x = y = 0.00, 0.05, respectively). Both samples show higher magnetization below spiral transition temperature (TS).

Herein we prepared five glass samples from the composition xLa2O3-(100-x)B2O3 (where x = 15, 20, 25, 30 and 35 mol%) and reported the physical, optical and gamma radiation shielding characteristics. The density of glass samples was increased from 3.1531 to 3.9443 g/cm3 with the addition of La2O3, while the molar volume is in the range of 34.2679–40.3849 cm3/mol. The refractive index of the glass samples is in the range of 1.6524–1.6541 with addition of La2O3 concentration. The optical band gap energy is found to be in the range of 3.08–3.14 eV. The transmission spectra for the La2O3 doped borate glasses in the wavelength range 200–2200 nm were reported and the results showed good transparency in visible region. This indicates that the prepared glasses are specifically showing superior transparency to visible light. The mass attenuation coefficient (μ/ρ) was simulated using MCNP code and the simulated data were compared with WinXcom data. The radiation shielding results showed that the different concentrations of La2O3 for the La2O3–B2O3 glass system have affected the μ/ρ of the glasses. Moreover, the sample with 35 mol% of La2O3 has higher μ/ρ compared with the rest of specimens especially at 0.347 MeV. The effective atomic number (Zeff) was also calculated and the highest Zeff values at all selected energies were for the sample with 35 mol% of La2O3, whereas the lowest Zeff were for the sample corresponding to 15 mol% of La2O3, which was 18.86 and 12.31 at 0.347 MeV respectively. The mean free path at 0.347 MeV and 0.511 MeV is very low for 35 mol% of La2O3 (1.88 and 2.70 cm respectively), which indicates that the sample with composition 35La2O3–65B2O3 can be used as effective and transparent photon shieling materials at low energy.

The glasses of samarium (0.1, 0.2, 0.5, 1.0, 1.5 and 2.0 mol %) doped lithium strontium borate samples were synthesized. The physical and optical properties are studied at ambient conditions and discussed in this study. XRD spectra reveals the no atomic order in structure (amorphous) present in these glasses. Infrared spectroscopic study reveals the structural units of borate viz., BO3 and BO4 group present in the matrix. Interestingly, it is found that as the rare earth concentration increases and beyond 1.5 mol % the luminescence intensity decreases due to non-bridging Sm3+ ions in the glass network. The peaks in absorption spectra are due to dipole transition from 6H5/2 to levels corresponds to (2S + 1)LJ excited states under the excitation wavelength of 402 nm. Judd–Ofelt theory applied to estimate dipole strength in terms of J–O parameters (Ω2, Ω4 and Ω6), oscillator strength (fexp and fcal), radiative transition possibility (AR), branching ratio (βR) and stimulated emission cross section (σ) of the glass samples. From Judd–Ofelt analysis the parameters obtained are shown for 1.50 mol % of Sm3+ doped lithium strontium borate (LSB) glasses studied, which were compared with other glasses. The obtained results suggest their potential candidature for using as solid state material lighting applications due their efficient orange emissions.

Glass samples with formula as Li2O–BaO–GdF3–SiO2:Sm2O3 were fabricated by melt quenching method. Their optical, physical and luminescence properties were studied, for their potential applications in photonic device working in visible region. The Sm3+ ions and nearby ligands bonding nature were determined from bonding parameters (δ) that in turn were calculated from LGF absorption spectra. Oscillator strength of different absorption bands and Judd–Ofelt (JO) parameters (Ωλ (λ = 2, 4, 6)) were measured. JO-parameters and refractive index have been used to valuate various radiative properties of Sm3+ ions emission transitions in prepared glasses to explore their potential application as visible lasers. Furthermore, the emission was studied by exciting the LGF glass samples with different wavelengths (λex = 275, 402 nm). The orange to red ratios at different wavelengths (λex = 275 nm and X-ray) were evaluated to measure the Sm3+-ions local disorder in the glass network. The decreasing trend in experimental decay time (τexp) with Sm3+-ion concentration increasing was observed due to energy transfer. Best fit for the prepared glass, when studied in the light of Inokuti–Hirayama model was obtained for S = 6 indicating dipole–dipole type of energy transfer. The intense visible (orange) emission, high stimulated emission cross-section (σe), branching ratios (βR), radiative transition probability (AR), and reasonable quantum efficiency were determined for transition from 4G5/2 to 6H7/2 in glass. This suggests Sm3+ doped glass shows potential use for development of devices (laser and photonic) working in visible (orange) region.

LGFDy glasses doped with Dy2O3 (0.1, 0.5, 1.0, 1.5 and 2.0 mol %) were synthesised by conventional melt quenching method and various properties are studied by absorption, Judd–Ofelt analysis, photoluminescence, X-ray excited luminescence, decay curve and CIE color chromaticity measurement. Judd-Ofelt parameters (Ω2, Ω4 and Ω6) are valuated form JO theory in order to estimate the radiative parameters of the Dy3+ ion excited states. For white light emission, Yellow/Blue (Y/B) ratio and CIE color coordinates for glasses under study are measured from the emission spectra. The energy transfer from Gd3+ to Dy3+ ions has been studied by exciting the glass with 275 nm photon. The higher value of σ (λp) and βR for 4F9/2 → 6H13/2 transition indicates its more potential use in laser application in yellow region. The correlated color temperature for LGFDy glasses is found to be 4264 K. The decay profile of fluorescent level 4F9/2 for different concentration of Dy3+ ions in the present glasses changes to non-exponential from single-exponential for higher concentration (≥0.5 mol %) of Dy3+ ions. Thus the chemical composition of glass and dopant (Dy3+ ions) concentration strongly influence the energy transfer mechanism. The lifetime non-exponential behavior is well fitted to IH-model for S = 6. The quantum efficiency for LBGFDy05 glass is found to be 86%. The systematic investigation signifies the potential of the studied LGFDy glasses for the laser and white light generation application.

Dy2O3-doped lithium lead gadolinium silicate glass was prepared for physical, optical, structural, X-ray induced luminescence and PL-luminescence properties for various potential applications in solid state lighting applications. JO parameters were estimated using JO theory. For the developed samples using emission spectra, CIE color coordinates and yellow/blue ratio are measured for white light emission. The transition 4F9/2 → 6H13/2 has higher value of stimulated emission cross section and radiative transition probability for all concentration showing its potential for laser emission. This transition has calculated and experimental branching ratio (βR) more than 0.50. The CCT value for developed glass samples is 4264 K which is more than warm CCT (CCT > 4000 K). The allowed indirect (n = 2) and direct (n = 1/2) band gaps were determined and found to be decreasing with increasing Dy2O3 concentration. The lifetime non-exponential nature is fitted well to IH model for S = 6. The energy transfer parameter (Q) increases and experimental lifetime decreases for concentration increase of Dy3+ ions in LPDy glasses. The investigation shows the potential of LPDy glasses for the laser and white light generation application.

The La2O3 added in (80-x) B2O3:10SiO2:10 CaO:xLa2O3 glass (where x = 10, 15, 20, 25 and 30 mol%) were prepared by melt-quenching technique have been investigated for x-ray shielding, physical and optical properties. The density of the glass samples found to increase which increasing La2O3 concentrations. The transmission spectra result demonstrated that the glass samples had high transparency similar with commercial window, corresponding to high visibility in the visible region as already observed. The mass attenuation coefficient (µm) were increased with the decreasing of kilovoltage peak (kVp) of an x-ray instrument, and increased with the increasing of La2O3 concentration. The half value layer (HVL) and ten value layer (TVL) of glass samples trend to decrease when the kVp of an x-ray instrument decrease and La2O3 concentrations increase. The trend of lead equivalent increase which Ln2O3 concentrations and the kVp of an x-ray instrument increasing. All results indicating the potential of the prepared glasses as Pb-free and high visibility for diagnostic x-ray shielding material.

The research work emphasizes on physical and luminescence properties of oxide and oxyfluoride phosphate glasses and discusses the energy transfer between Gd3+ and Sm3+ ions. Lithium gadolinium oxide and oxy-fluoride phosphate glasses doped with Sm3+ ions were prepared by conventional melt quenching technique. Subsequently the physical and luminescence properties were investigated systematically to understand their behavior. The density of the prepared glass samples show high in oxide glasses as compared to oxy-fluoride glasses, and the density of both glass samples increase with increase in the Sm2O3 concentrations. In total, ten signature Sm3+ ion peaks were observed in the UV-Vis-NIR absorption spectra. In photoluminescence spectra the oxy-fluoride glass samples show higher excitation and emissions intensity than oxide glasses. The emission intensity increases up to 1mol% concentration of Sm3+ ions and then decreases due to non-radiative energy transfers. The same is observed in case of radioluminescence emission spectra. The calculated J-O intensity parameters show Ω2 > Ω4 > Ω6 trend. From Judd-Ofelt analysis, these glasses exhibit high potential for using as laser host medium. The life time recorded at the excitation and emission wavelength 401 nm and 598 nm respectively and it is observed that the life time decreases with increase in the Sm3+ ions concentration. The CIE coordinates positioned in the orange region of CIE diagram. The properties evaluated in the present work indicate that these glasses can be a good candidate of orange LEDs applications.

Traditional melt-quenching technique is adopted for synthesis of Sm2O3 doped lithium barium gadolinium silicate (LBGS: Li2O-BaO-Gd2O3-SiO2) glasses. These glass samples are characterized by different spectroscopic techniques under ambient conditions. Density and molar volume of the present LBGS glass samples increase with increasing Sm3+ ion-concentration. JO intensity parameters Ωλ (where λ = 2, 4 and 6) are evaluated by using Judd-Ofelt theory and Ω4 > Ω2 > Ω6 trend is observed. Furthermore, these parameters are used to evaluate radiative properties like radiative transition probability, branching ratio, radiative lifetime and stimulated emission cross-section for state 4G5/2 of Sm3+ ion. The measured color coordinates for the title glass fall within orange region of CIE diagram. For the present LBGS glasses, the correlated color temperature values are less than warm. The lifetime for the 4G5/2 decreases from 2.468 to 0.566 ms when concentration increases from 0.1 to 2.0 mol% of Sm3+ ions. The analysis of non-exponential behavior of the decay profile through Inokuti-Hirayama model for S = 6 indicates that the energy transfer between Sm3+ ions is due to dipole-dipole interactions. Further energy transfer parameters (Q), critical distance (Ro, A) and donor-acceptor interaction parameters (CDA x 10−40 cm6/s) of Sm3+ ions doped LBGS glasses were evaluated and compared to other glasses. From the evaluated results it is suggested that the present novelty of the work emphasizes on new matrix LBGS doped with Sm3+ ions showing increasing energy transfer rate with increasing in concentration of Sm2O3 content indicating these glasses are potential candidate for orange-light emitting device applications.

The physical and luminescent properties of Sm3+-doped oxide and oxy-fluoride phosphate glasses were investigated. The glass samples with chemical composition of 69P2O5-10BaO-10ZnO-10Gd2O3-1Sm2O3 and 69P2O5-10BaO-10ZnO-10GdF3-1Sm2O3 were prepared by conventional melt quenching technique. The prepared glass samples were characterized with density, molar volume, refractive index, FTIR, UV-Vis-NIR, photoluminescence, radio luminescence, decay time profile and CIE diagram. The density and refractive index of the oxide glass have higher values as compared to the oxy-fluoride glass. The FTIR spectra show the reduction of O-H group in oxy-fluoride glass. The characteristic peaks of Sm3+ are observed at 360, 372, 402, 438, 419, 473, 944, 1077, 1227, 1373, 1474, 1529 and 1585 nm in UV-VIS-NIR spectra. These peaks are related respectively to the transitions from ground state 6H5/2 to 4D3/2, 6P7/2, 6P3/2, 4I11/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2 and 6F1/2 excited states. From photoluminescence and radio-luminescence it is observed that the oxy-fluoride glass samples show better emission intensity than the oxide glass. The Judd-Ofelt theory (J-O theory) was used to find J-O intensity Ωλ (λ = 2,4 and 6) parameters and radiative properties such as transition probability, stimulated emission cross section and branching ratios for titled glasses. The trend observed in the J-O parameters is Ω4 >Ω2 >Ω6. The transition probability, emission cross section and branching ratio have the highest values for the 4G5/2 → 6H7/2 transition. The CIE coordinates of the prepared glass samples are positioned in the orange region and the CCT value is 3776.105 for oxide and oxyfluoride glass. The oxy-fluoride glass has shorter decay time as compared to the oxide glass and it is recorded to be 1.62 and 1.32 ms for oxide and oxy-fluoride respectively. According to the results obtained in this work, it is obvious that these glass samples can be good candidate materials for producing cool orange light.

50Li2O - 20MO - (30-x)B2O3 - xEu3O3 where (M = Mg, Ca, Sr, Ba) and (x = 0, 0.1, 0.3, 0.5, 1.0, 3.0, 5.0, 7.0 glasses were prepared and characterized to study their physical & optical properties using spectroscopic measurements such as UV-Visible spectra, Luminescence spectra, Radio-Luminescence, X-Ray Luminescence etc. The electronic transitions in the UV-VIS and NIR regions are assigned to the 7F0 → 5L6, 7F0 → 5D2, 7F0 → 5D1, 7F0 → 7F6 and 7F1 → 7F6 levels centered at 394, 465, 532, 2092 and 2202 nm due to their transitions from 7F0 ground state to various excited states of Eu3+ ions, respectively. Structural studies were analyzed using Raman Spectra. Five transition bands of luminescence spectra have been observed by using an excited wavelength of 394 nm. With five emission transitions of 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 as was reported previously in literature at 578, 591, 591, 614, 653 and 702 nm, respectively. The lower phonon energy (∼971 cm−1) and higher phonon side band intensity is observed at 5.0 mol% Eu2O3 content doped LBaB glasses while higher phonon energy (∼1176 cm−1) and lower phonon intensity observed for 5.0 mol% Eu2O3 content doped LMgB glasses. The chromaticity coordinates of Eu3+ ions in all LiMOB glasses falls in the reddish orange region. The radioluminescence (RL), emission spectra were corresponding to those from PL measurements. From RL measurement, the integral scintillation efficiency of developed glass was determined at 11.2% when compared with BGO crystal.

Li2O-BaO-Gd2O3-SiO2 glasses with different concentration of Eu3+ ions were developed by the traditional melt quenching technique and characterized via FTIR, absorption, excitation, emission and CIE color coordinates analysis for visible red emission application. The FTIR shows strong band at position 740 cm−1 which is attributed to Si-O-Si symmetric stretching mode. Density and molar volume of LBGSEu glasses increases with Eu3+ ions concentration. The covalent nature of bond between the Eu3+ ions and surrounding ligands was confirmed from the bonding parameter (δ). From absorption spectra JO-parameters and oscillator strength are evaluated for LBGSEu6 glass. From JO-parameters, Eu3+ ions have asymmetric coordination environment and stronger covalency. The phonon line PSB (22,522 cm−1) confirm the phonon energy ≈971 cm−1, that corresponds to the energy of one phonon associated with maximum energy of the vibrational mode couple to Eu3+ ions. Under 275 nm and 393 nm excitation, intense red emission was observed at 613 nm, we observe efficient energy transfer phenomena from Gd3+ → Eu3+ in these glasses. Increasing trend of IR with increasing concentration of Eu2O3 indicates the asymmetric environment around Eu3+ ions in LBGS. Moreover, from JO analysis, LBGS glasses have high capability for red laser device with high lasing power and energy extraction ratio. The fluorescence lifetimes show decreasing trend in lifetime with increasing concentration of Eu2O3 is due to radiative transition. From CIE color coordinate, the CIE color coordinates of LBGSEu6 glass fall in reddish region close to orange region and can be useful for optical display devices.

Dy3+-doped Li2O-BaO-Gd2O3-SiO2 (LBGS) glasses were prepared by traditional melt quenching techniques and characterized through absorption and emission spectra. Tauc's plot for allowed direct and indirect transition are shown studied and observed in the range of 3.5 (eV) to 2.9 (eV). The variation in the band gap with the addition of Dy2O3 is due to structural changes in the glass matrix. For 0.5 mol% of Dy3+ ions doped LBGS glasses Judd-Ofelt analysis was carried out further these parameters were used to study their radiative properties for the excited luminescent levels of Dy3+ ions. White light generation was evaluated as a function of the Dy3+ ions concentration by measuring yellow-to-blue emission intensity ratios and CIE chromaticity coordinates. The non-exponential decay were observed for glasses doped beyond 0.1 mol% and were well fitted to IH-model for S = 6 (dipole-dipole interaction). The non-exponential behavior and life time quenching have been accredited to the energy transfer through dipole-dipole interaction among the excited and unexcited Dy3+ions. Pulse X-Ray decay time has measured for 0.5 mol% of Dy3+ ions doped LBGS glass. CIE-1931 chromaticity coordinates and decay profile analysis were studied. The correlated color temperature (CCT) for LBGS-0.5Dy is found to be 3621 K at λexc = 350 nm. The quantum efficiency (η) for the title LBGS-0.5Dy glass is found to be 74%. The highest values for radiative transition probability (AR), emission cross section (σ(λP)), experimental and calculated branching ratio (βR) have been observed for 4F9/2 → 6H13/2 at 576 nm.

Phosphate glasses with chemical compositions (mol %) of (66-x) P2O5-17Li2O-17Gd2O3-xEu2O3 and (66-x) P2O5-17Li2O-17GdF3-xEu2O3 (where x = 0.05, 0.1, 0.5, 1.0 and 2.0) were prepared with conventional melt quenching technique. The physical and luminescence properties of prepared glass samples were investigated systematically. The density and refractive index increase with increasing concentration of Eu2O3. The characteristic intense red emission at 612 nm corresponding to the transition (5D0 →7F2) of Eu3+ ions has been observed for both oxide and oxy-fluoride glass samples. The Judd-Ofelt (J-O) theory is used to evaluate the properties such as oscillator strengths, J-O intensity parameters, radiative transition probabilities, stimulated emission cross section and branching ratios for present glasses. The J-O intensity parameters follow Ω4> Ω2> Ω6 trend. The oxyfluoride glasses show longer decay time as compared to oxide glasses. Hence from the properties it is concluded that, the present glass samples can be a good candidate for red light emitting source in solid state lighting applications.

In this work, glasses of composition (30 – x)TeO2–30B2O3–10ZnO–30BaO–xHo2O3x = 0.00 0.05, 0.10, 0.50, 1.00, 1.50 mol % have been prepared through the melt quenching method. In order to characterize and explore their structural properties, we measured the density, refractive index of the glass which shows increasing trend with increase in Ho2O3 concentration also FTIR and XRD spectrum is used to study the structural properties of the developed glasses. XRD shows amorphous structure of the prepared glasses. FTIR shows B–O stretching (BO)3– units and Symmetrical stretching vibration of Te–O in TeO3. The electronic states belonging to the 4f configuration of trivalent Ho3+ were determined from the absorption spectra. Judd–Ofelt (JO) intensity analysis had been performed for oscillator strength and JO parameters were estimated to be Ω2 > Ω6 > Ω4. The emission spectra of the Ho doped glass samples were monitored at λexi = 454 nm. In the PL spectra, the characteristic emission bands due to f–f transition of Ho3+ were confirmed for the glass system, the transition 5I8 → 5G6 of Ho3+ ion is a hypersensitive transition and hence host dependent. For the transition 5F4 → 5I8 stimulated emission cross section is found to be 1.79 × 10–22 cm2.

Au LIII edge X-ray absorption spectroscopic measurements were carried out over a series of Au nanoparticles embedded glasses with SnO2 and SeO2. The results obtained from EXAFS and XANES confirms the typical characteristics and structure of gold nanoparticles in these glasses. Raman analysis was performed to understand the structure of the glass. XANES data reveal that these glasses show Au0 and Au+1 oxidation state depending on reducing agent. EXAFS refinements were performed using ARTEMIS software to calculate bond lengths, R-factor and Debye–Waller factor on these glasses.

In this work, Bi2MoO6 and Bi(2-x)DyxMoO6 (x = 0.05, 0.10, 0.15 and 0.20 % by mol) phosphors were synthesized by high- temperature solid-state reaction method. The finely powdered mixtures were sintered at 500, 550, 600, 650 and 700 °C for 12 h in air atmosphere. The structural characteristics of Bi2MoO6 phosphors were examined and confirmed by X-ray diffraction (XRD). The optical spectra were measured and confirmed signature peaks of Dy3+ ions in Bi2MoO6 phosphors. The emission spectra of phosphors exhibited emission bands at 482, 575, 663 and 750 nm corresponding to 6H15/2, 6H13/2, 6H11/2 and 6H9/2 transitions from the ground state (4F9/2). The emission of Bi(2-X)DyXMoO6 (x= 0.10) was shown greendish-yellow color, calculated by CIE 1931 color coordinate.

The novel shielding materials from (55-x) SiO2: 13B2O3: 1Al2O3: 4.5BaO: 6.3CaO: 0.2Sb2O3: 20Na2O: xCeO2 where x = 1, 2, 3, 4 and 5 mol% glasses have been fabricated at different CeO2 concentration by melt-quenching technique and studied the luminescence and radiation shielding properties. The transmission spectra show red-shift in UV range, due to higher Ce concentration in the glass matrix. The emission bands of glasses around 393 nm were observed from the 5d-4f transition of an electron in the Ce3+ ion. In the present glass matrix doped with CeO2 shows oxidation state of both Ce3+ and Ce4+. Decay curves are also investigated and found to be less than 100 ns. The X-rays shielding properties such as half-value layer (HVL), tenth value layer (TVL), mean free path (MFP), and linear attenuation coefficients (μ) of glass were investigated. The HVL values of glass samples at 5 mol% has better shielding behavior than commercial x-ray windows. The obtained results from the measurements suggests that these glasses are potential host for radiation shielding material application and also UV emitting device applications.

The Co0.5Ni0.5CexSmyFe2-x-yO4 (CNCSF) XRD pattern revealed the purity of the samples without any secondary phase. The crystallite size CNCSF are in nano range. Further, the calculated lattice parameter of CNCSF are found to increasing with the RE content. From SEM micrographs surface morphology and the microstructure of the CNCSF was studied. The porous nature of the samples is revealed by SEM, which will aid in increasing their sensing response. Energy dispersive X-ray spectroscopy (EDS) patterns have confirmed the stoichiometric presence of Co2+ Ni2+, Ce3+, Sm3+ and Fe3+, those are used to prepare the CNCSF. The dielectric behaviour is similar to that of conventional spinel ferrite structures, in that the dielectric constant is highest at low frequencies and decreases at higher frequencies due to electron hopping, resulting in dielectric dispersion. Only one semicircle is seen in each Cole-Cole plot, which has uncovered that the contribution to conductivity is predominantly from the grain boundaries. At room temperature, the gas sensing responses of CNCSF thin films were investigated. For liquified petroleum gas (LPG), the gas sensing characteristics of the prepared thin films were investigated. At room temperature, the x = 0.03 thin films showed excellent sensitivity to liquified petroleum gas. The sensing response and recovery time of all of the thin films that had been prepared were reported. The sensing response of x = 0.03 thin films was highly stable over a period of 60 days on exposure to LPG (1000 PPMv), according to the stability analysis. The sample thin film with x = 0.03 can be utilized in gas sensor technology, particularly for the detection of LPG at room temperature, due to its increased sensitivity, quick response and recovery times, and stability.

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The present work focuses on lead-free glasses, their shielding behavior, and other optical studies. The glass composition with xGd2O3+10La2O3+10ZnO+(79-x) B2O3+1Dy2O3, x = 0, 5, 10, 15, 20 mol% were prepared to the characterization on physical, absorption spectra, photo-, radioluminescence, and radiation shielding properties. In the experimental results, the density of Gd-1Dy glass samples increases with the increase of Gd3+ ions concentrations. The ten-strong peak in the 5Gd-1Dy glass of absorption spectra in UV–Vis–NIR regions. The white photoluminescence spectra base of Gd-1Dy glass samples can be generated under excitation at 351 nm makes the strongest emission of Dy3+ ions and excitation through energy transfer from Gd3+ in Gd-1Dy glass samples with 275 and 351 nm. This strong white emission of Dy3+ ions also strong in x-ray luminescence and performs the integral scintillation efficiency of 33% when compared with BGO crystal. The radiation shielding properties in the diagnostic medicine energies region are correlated, the values of glass samples better than commercial windows, bricks, and concrete. The HVL values of glass sample at 15 and 20 mol% of Gd2O3 has been found better than X-ray windows. The corollaries of Gd-1Dy glass samples can be a candidate for radiation detector and lead-free radiation shielding materials in future.

The work focuses on developing new alternative radiation shielding and visible luminescent glasses from (55-x) SiO2: 13B2O3: 1Al2O3: 4.5BaO: 6.3CaO: 0.2Sb2O3: 20Na2O:xPr2O3 where x = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 mol% composition. Glasses have been fabricated by melt-quenching technique. Four emission bands at 484 nm, 528 nm, 605 nm, and 645 nm were observed. Highest emission intensity is observed for 1.0mol% of Pr3+ ions whereas radiation shielding ability showed better results for higher concentration of Pr3+ ions. Prominent blue emission around 482 nm is been strong in the present glasses. The radiation shielding properties have been evaluated and results show that all glass samples are better radiation shielding properties than ordinary concrete, red brick, and commercial windows.