A series of borate glasses with the composition x(SrO)·(50 – x)V2O5·0.5(B2O3) where x = 0, 0.1, 0... more A series of borate glasses with the composition x(SrO)·(50 – x)V2O5·0.5(B2O3) where x = 0, 0.1, 0.2, 0.3 and 0.4 were prepared by melt-quenching technique. The non-crystalline nature of the glasses has been established by XRD studies. Room temperature density and DC electrical conductivity of the samples were investigated in the temperature range of 300 K to 443 K. The molar volume and oxygen packing density (OPD) were estimated. The results show that the density, molar volume and OPD decrease with the increasing of SrO mole fraction. The DC electrical conductivity data has been analyzed in the light of Mott’s small polaron hopping (SPH) model and the activation energies were estimated. The conductivity was observed to rapidly fall and activation energy was found to increase when SrO was incorporated into the glass network. This may indicate that Sr+ ions have not contributed to the total conductivity and the observed conductivity may be of polaronic type only, which is due to the h...
Abstract: The thermal and structural properties of melt-quenched Li2O and Na2O doped borate glass... more Abstract: The thermal and structural properties of melt-quenched Li2O and Na2O doped borate glasses were investigated. The noncrystalline nature of the as-quenched samples has been established by XRD studies. The structural and thermal properties of the present glasses have been studied using Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The formation of both BO3 and BO4 units in the studied samples has been ascertained by the FTIR studies. The nonlinear variation of peak positions of B-O bonds of stretching vibrations validate the occurrence of mixed alkali effect. The glass transition temperature (Tg) and thermal stability (∆t) exhibited a non-linear variation with increase in (Li2O+Na2O) content. With increasing the concentration of dopants, the Tg and ∆t respectively exhibited maxima and minima at x=0.30. This kind of behavior has been attributed to the structural modifications occurring in the network as a function of compositional ...
... This linear relation indicates the existence of a single mechanism for both conduction and di... more ... This linear relation indicates the existence of a single mechanism for both conduction and dielectric relaxation processes operated in the glass ... That is, as the temperature increases two effects on the dipolar polarization may occur: (i) it weakens the intermolecular forces and ...
The glasses of the type (Li 2 O) x (CoO) 0.2 (B 2 O 3 ) 0.8− x and (Li 2 O) 0.2 (K 2 O) x (Co... more The glasses of the type (Li 2 O) x (CoO) 0.2 (B 2 O 3 ) 0.8− x and (Li 2 O) 0.2 (K 2 O) x (CoO) 0.2 (B 2 O 3 ) 0.6− x were prepared by melt quench technique and their non-crystallinity has been established by XRD studies. The glasses were investigated for room ...
IOP Conference Series: Materials Science and Engineering, 2009
Two series of cobalt-borate glasses doped with Li2O and K2O in single and mixed proportions have ... more Two series of cobalt-borate glasses doped with Li2O and K2O in single and mixed proportions have been synthesized by melt quenching method and investigated for ac conductivity in the frequency range of 50Hz to 5MHz and temperature range of 310K to 610K. From the measured total conductivity, the pure ac component and its frequency exponent, s were determined. In the
Single and mixed transition metal ions doped tellurite glasses were investigated for dielectric p... more Single and mixed transition metal ions doped tellurite glasses were investigated for dielectric properties in the frequency range 50 Hz to 5 MHz and temperature range 300500 K. From the total conductivity derived from the dielectric spectrum the frequency exponent, s, and dc ...
A series of borate glasses with the composition x(SrO)·(50 – x)V2O5·0.5(B2O3) where x = 0, 0.1, 0... more A series of borate glasses with the composition x(SrO)·(50 – x)V2O5·0.5(B2O3) where x = 0, 0.1, 0.2, 0.3 and 0.4 were prepared by melt-quenching technique. The non-crystalline nature of the glasses has been established by XRD studies. Room temperature density and DC electrical conductivity of the samples were investigated in the temperature range of 300 K to 443 K. The molar volume and oxygen packing density (OPD) were estimated. The results show that the density, molar volume and OPD decrease with the increasing of SrO mole fraction. The DC electrical conductivity data has been analyzed in the light of Mott’s small polaron hopping (SPH) model and the activation energies were estimated. The conductivity was observed to rapidly fall and activation energy was found to increase when SrO was incorporated into the glass network. This may indicate that Sr+ ions have not contributed to the total conductivity and the observed conductivity may be of polaronic type only, which is due to the h...
Abstract: The thermal and structural properties of melt-quenched Li2O and Na2O doped borate glass... more Abstract: The thermal and structural properties of melt-quenched Li2O and Na2O doped borate glasses were investigated. The noncrystalline nature of the as-quenched samples has been established by XRD studies. The structural and thermal properties of the present glasses have been studied using Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The formation of both BO3 and BO4 units in the studied samples has been ascertained by the FTIR studies. The nonlinear variation of peak positions of B-O bonds of stretching vibrations validate the occurrence of mixed alkali effect. The glass transition temperature (Tg) and thermal stability (∆t) exhibited a non-linear variation with increase in (Li2O+Na2O) content. With increasing the concentration of dopants, the Tg and ∆t respectively exhibited maxima and minima at x=0.30. This kind of behavior has been attributed to the structural modifications occurring in the network as a function of compositional ...
... This linear relation indicates the existence of a single mechanism for both conduction and di... more ... This linear relation indicates the existence of a single mechanism for both conduction and dielectric relaxation processes operated in the glass ... That is, as the temperature increases two effects on the dipolar polarization may occur: (i) it weakens the intermolecular forces and ...
The glasses of the type (Li 2 O) x (CoO) 0.2 (B 2 O 3 ) 0.8− x and (Li 2 O) 0.2 (K 2 O) x (Co... more The glasses of the type (Li 2 O) x (CoO) 0.2 (B 2 O 3 ) 0.8− x and (Li 2 O) 0.2 (K 2 O) x (CoO) 0.2 (B 2 O 3 ) 0.6− x were prepared by melt quench technique and their non-crystallinity has been established by XRD studies. The glasses were investigated for room ...
IOP Conference Series: Materials Science and Engineering, 2009
Two series of cobalt-borate glasses doped with Li2O and K2O in single and mixed proportions have ... more Two series of cobalt-borate glasses doped with Li2O and K2O in single and mixed proportions have been synthesized by melt quenching method and investigated for ac conductivity in the frequency range of 50Hz to 5MHz and temperature range of 310K to 610K. From the measured total conductivity, the pure ac component and its frequency exponent, s were determined. In the
Single and mixed transition metal ions doped tellurite glasses were investigated for dielectric p... more Single and mixed transition metal ions doped tellurite glasses were investigated for dielectric properties in the frequency range 50 Hz to 5 MHz and temperature range 300500 K. From the total conductivity derived from the dielectric spectrum the frequency exponent, s, and dc ...
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