Optical absorption and heating rate dependent glass transition in vanadyl doped calcium oxy-chloride borate glasses

Dahiya, Manjeet S.; Khasa, Satish; Agarwal, Ashish

doi:10.1016/j.molstruc.2015.01.023

Cited by 33 publications

(6 citation statements)

References 42 publications

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“…x D (g/cm 3 ) [27,28] containing vanadyl ions. The oxy-chloride systems are presumed to result in volatilization of chlorine during melting, so the final composition may differ a bit from the actual composition [29].…”

Section: Sample Codementioning

confidence: 99%

Physical, thermal, structural and optical absorption studies of vanadyl doped magnesium oxy-chloride bismo-borate glasses

Dahiya

Khasa

Agarwal

2015

Journal of Asian Ceramic Societies

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Please cite this article in press as: M.S. Dahiya, et al., Physical, thermal, structural and optical absorption studies of vanadyl doped magnesium oxy-chloride bismo-borate glasses, J. Asian Ceram. Soc. (2015), http://dx. a b s t r a c tOxy-chloride bismuth-borate glasses with composition xMgCl 2 ·(30 − x)MgO·20Bi 2 O 3 ·50B 2 O 3 containing 2 mol% doping of V 2 O 5 (x = 12, 15, 20, 25 and 30) are prepared by melt-quenching technique. The structural, thermal and optical behaviors are explained by analyzing the data obtained from density (D), molar volume (V m ), theoretical optical basicity ( th ), differential scanning calorimetry (DSC), FTIR and UV-vis results. A decrease in D and increase in V m (except for sample MBV3 for which D is maximum) on increasing chloride content suggests the formation of non-bridging oxygen atoms. Maximum glass transition temperature (T g ) and crystallization temperature (T x ) have been observed for sample MBV3. The glass stability (S) and stability ratio (S/T g ) have been calculated from the values of T g and T x and both are having maximum values for sample MBV3. Study of the FTIR spectra in the mid-IR range reveals the presence of both triangular and tetrahedral coordinated boron. The optical studies through UV-vis spectral analysis show non-sharp edge. The optical band gap (E g ) is also maximum for sample MBV3.

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Section: Sample Codementioning

confidence: 99%

Physical, thermal, structural and optical absorption studies of vanadyl doped magnesium oxy-chloride bismo-borate glasses

Dahiya

Khasa

Agarwal

2015

Journal of Asian Ceramic Societies

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“…The optical absorption data were used to calculate optical band gap and band tailing [26]. The differential scanning calorimetric (DSC) studies of the samples in the bulk form amounting to 30-40 mg were carried out on a simultaneous thermal analyzer (Perkin Elmer STA6000) [27,28].…”

Section: Methodsmentioning

confidence: 99%

“…5. The reason for recording all thermographs at same heating rate is the heating rate dependence of characteristic temperatures [60,28]. An endothermic shift (or upward shift) around 480 • C is evidence from all the DTA thermographs.…”

Section: Differential Thermal Analysis (Dta)mentioning

confidence: 99%

Optical and thermal investigations on vanadyl doped zinc lithium borate glasses

Dalal

Khasa

Dahiya

et al. 2015

Journal of Asian Ceramic Societies

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Using standard melt-quench technique, transition metal oxide (2 mol% of V 2 O 5) doped glasses having composition xZnO•(30 − x)Li 2 O•70B 2 O 3 (x = 0, 2, 5, 7 and 10) are prepared. The density (D) is measured using buoyancy and found to be lying between 2.21 and 2.45 g/cm 3 with an increasing trend on substituting ZnO contents in place of Li 2 O. The theoretical optical basicity (th) is calculated and found to increase with increasing inclusion of ZnO indicating an increase in the ionic character. The molar refraction (R m), refractive index (n r) and molar polarizability (˛m) are calculated and explained on the basis of structural changes. The optical absorption spectra have been used to evaluate the values of optical band gap (E opt) and band tailing parameter (B). It is observed that E opt decreases with the increasing contents of ZnO in base glass matrix. The decrease in E opt is an evidence of enhancement in the number of non-bridging oxygen atoms (NBOs) thereby increasing the four-coordinated boron atoms. The as-quenched samples in bulk form are subjected to differential thermal analysis (DTA) to assess the glass transition temperature (T g), which is 476 • C for pure lithium borate glass. The variations suggest that the structure is being modified by the substitution of ZnO.

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“…The ionic polarization is temperature independent but the orientational and the migrational polarizations are temperature dependent and while the former is expected to decrease due to thermal agitation the later is expected to increase with the rise in temperature. Study of literature [17,18,27,28,33,[38][39][40] suggests that in dielectric permittivity ε * of a sample is due to (i) rotation of ions around their negative sites and (ii) short range dipole transport (hopping).…”

Section: Dielectric Lossmentioning

confidence: 99%

“…Our recent studies concern various properties of different vanadium doped borate glasses [16][17][18]. Kashif et al have studied the effect of alkali content on AC conductivity of borate glasses containing two transition metals [19].…”

Section: Introductionmentioning

confidence: 99%

Structural, Physical, Electrical and Dielectric Properties of Magnetic Glasses: xFe₂O₃+(30-x)V₂O₅ + 30Na_2O + 40B₂O₃ with x=0 to 15

et al. 2019

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Magnetic glasses compositions: xFe2O3 + (30 − x)V2O5 + 30Na2O + 40B2O3 (x = 0, 2, 3, 5, 7, 10, and 15), abbreviated as FVNBx, are prepared with conventional melt-quenching technique, and the structural, physical, and electrical properties of compositions are investigated. The amorphous nature of the FVNBx glasses is confirmed using X-ray diffraction technique. It is found that the density of the glasses increases with x. The molar volumes calculations are based on the molar mass and the density data, which are then correlated with the structural changes. The decrease in the theoretical optical basicity shows marginal increase in the covalence of oxygen, when the V2O5 content is replaced with Fe2O3. The Fourier transform infrared spectroscopy that is carried out in the mid-IR region, shows the absence of the six-atomic (B3O3) boroxol rings. In this paper, the IR absorption bands corresponding to the combined contributions of tri and tetra borate vibrations are identified. The distinct IR spectra of the samples with different x indicates that the iron acts as a strong glass modifier, and brings only noticeable microstructural changes in the glass structures. Fe2O3 is believed to act as both glass former and glass modifier. The increase of DC electrical conductivity with temperature indicates a semiconducting nature of the glasses. The replacement of V2O5 by Fe2O3, even by 1 mol%, decreases the DC conductivity by an order of magnitude, and increases the activation energy by a factor of two. Composition, frequency, and temperature dependence of different dielectric parameters, namely dielectric constant ε , dielectric loss ε , loss tangent tan(δ), electrical modulus M * , etc., are also analyzed.

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Optical absorption and heating rate dependent glass transition in vanadyl doped calcium oxy-chloride borate glasses

Cited by 33 publications

References 42 publications

Physical, thermal, structural and optical absorption studies of vanadyl doped magnesium oxy-chloride bismo-borate glasses

Physical, thermal, structural and optical absorption studies of vanadyl doped magnesium oxy-chloride bismo-borate glasses

Optical and thermal investigations on vanadyl doped zinc lithium borate glasses

Structural, Physical, Electrical and Dielectric Properties of Magnetic Glasses: xFe₂O₃+(30-x)V₂O₅ + 30Na_2O + 40B₂O₃ with x=0 to 15

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Optical absorption and heating rate dependent glass transition in vanadyl doped calcium oxy-chloride borate glasses

Cited by 33 publications

References 42 publications

Physical, thermal, structural and optical absorption studies of vanadyl doped magnesium oxy-chloride bismo-borate glasses

Physical, thermal, structural and optical absorption studies of vanadyl doped magnesium oxy-chloride bismo-borate glasses

Optical and thermal investigations on vanadyl doped zinc lithium borate glasses

Structural, Physical, Electrical and Dielectric Properties of Magnetic Glasses: xFe2O3+(30-x)V2O5 + 30Na2O + 40B2O3 with x=0 to 15

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Product

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Structural, Physical, Electrical and Dielectric Properties of Magnetic Glasses: xFe₂O₃+(30-x)V₂O₅ + 30Na_2O + 40B₂O₃ with x=0 to 15