Ceramic and polymeric solid electrolytes for lithium-ion batteries

Infrared absorption spectra of sodium phosphate glasses, Na2O=30–50 mol%, have been studied in the region of 400–2000 cm−1. Spectra were analyzed to determine the relative intensity of the IR bands responsible for the different phosphate units. Spectral analyses has shown that the substitution of P2O5 by Na2O influences the intermediate range order of the glass matrix. Increasing Na2O content leads to a gradual degradation of the phosphate ring type structures, with consequent depolymerization causing compaction of the glass matrix. Analyses of IR spectra illustrates the reorganization effects of Na2O in the phosphate matrix.

Infrared spectra of sodium phosphate glasses

Piezoelectric materials for acoustic wave applications have changed markedly over the past 20 years in terms of both the types of materials available and the quality of individual samples. The total family of acoustic wave materials now includes piezoelectric glass-ceramics having crystallographic and polar orientation and crystals having symmetry classes mm2, 32, 3m, 4mm, 6mm, and 4/spl macr/3m. The symmetry classes 6mm and 4/spl macr/3m also occur frequently in piezoelectric semiconductor materials that are now available in both bulk and thin-film configurations. In this paper, we bring together and extract the various reported values of the material constants mainly of interest for surface acoustic wave (SAW) device applications. We identify for the user community those sets of constants from which SAW design calculations can reliably be made, and discuss the constants and their reliability for langasite, lithium niobate/lithium tantalate, and dilithium tetraborate. The relevant material constants include: mass density /spl rho/, elastic stiffness c/sub ij/, piezoelectric stress e/sub ij/, dielectric permittivity /spl epsiv//sub ii/, and the thermal expansion coefficients /spl alpha//sub ii/. Except for the semiconductor materials, only data published after 1978 are included, since the reference literature (Landolt-Bornstein) amply covers those years prior to 1978. >

Piezoelectric materials for acoustic wave applications

To investigate the modification effect of the modifier ZnO on boro-tellurite glass, a series of glasses with compositions 50B 2 O 3 –(50− x )ZnO– x TeO 2 have been prepared by conventional melt quenching technique. Amorphous nature of the samples was confirmed through X-ray diffraction technique. Optical absorption and IR structural studies are carried out on the glass system. The optical absorption studies revealed that the cutoff wavelength increases while optical band gap ( E opt ) and Urbach energy decreases with an increase of ZnO content. Refractive index evaluated from E opt was found to increase with an increase of ZnO content. The compositional dependence of different physical parameters such as density, molar volume, oxygen packing density, optical basicity, have been analyzed and discussed. The IR studies showed that the structure of glass consists of TeO 4 , TeO 3 /TeO 3+1 , BO 3 , BO 4 and ZnO 4 units.

Optical, physical and structural studies of boro-zinc tellurite glasses

Investigation of bismuth borate glass system modified with barium for structural and gamma-ray shielding properties.

Problem statement: Systematic series of ZnO-TeO 2 glasses with mole fraction of 0.10-0.40 ZnO content with an interval of 0.05 were studied t o obtain their physical and optical properties. Approach: All the glass samples were synthesized by rapid me lting quenching method under controlled conditions, while their refractive indic es (n) were measured by the EL X-02C high precision ellipsometer. The room temperature absorption of al l glass samples were determined using Camspec M350 double beam UV-visible spectrophotometer. The infrared (IR) spectra of each glass samples were recorded with Thermo Nicolet Fourier Transform-Infrared (FT-IR) spectrophotometer. Their physical properties were measured and the amorphous nature was confirmed by the x-ray diffraction technique. Results: The increase of refractive index of the TeO 2-ZnO glasses with the addition of ZnO was best explained in terms of either electron dens ity or polarizability of the ions. The absorption e dge shift to higher energy (shorter wavelength) with in creasing ZnO content was observed in this glass. The optical band gap (E opt ) of zinc tellurite glass decreases with increasing of ZnO content probably due to the increment of Non-Bridging Oxygen (NBO) ion contents which eventually shifted the band edge to lower energies. Conclusion/Recommendation: The physical and optical properties of zinc tellurite glasses were found generally affected by the changes in the glass composition. FTIR spectra of zinc tellurite glass revealed broad, weak and stron g absorption bands in the investigated range of wav e numbers from 4000-400 cm -1 which associated with their corresponding bond modes of vibration and the glass structure. The addition of ZnO into Te O 2 glass network shifted the major band from 626 cm -1 (for pure TeO 2 glass) to the band at around 669 cm -1 .

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Synthesis and optical properties of ZnO-TeO2 glass system

Zinc borotellurite glasses doped with lanthanum oxide were successfully prepared through melt-quenching technique. The amorphous nature of the glass system was validated by the presence of a broad hump in the XRD result. The refractive index of the prepared glass samples was calculated by using the equation proposed by Dimitrov and Sakka. The theoretical value of molar refraction, electronic polarizability, oxide ion polarizability and metallization criterion were calculated by using Lorentz-Lorenz equation. Meanwhile, expression proposed by Duffy and Ingram for the theoretical value of optical basicity of multi-component glasses were applied to obtain energy band gap based optical basicity and refractive index based optical basicity. The optical basicity of prepared glasses decreased with the increasing concentration of lanthanum oxide. Metallization criterion on the basis of refractive index showed an increasing trend while energy band gap based metallization criterion showed a decreasing trend. The small metallization criterion values of the glass samples represent that the width of the conduction band becomes larger which increase the tendency for metallization of the glasses. The results obtained indicates that the fabricated glasses have high potential to be applied on optical limiting devices in photonic field.

Optical basicity and electronic polarizability of zinc borotellurite glass doped La3+ ions

A series of ternary phosphate glasses in the form of (PbO)x(ZnO)60-x(P2O5)40 where x = 0–60 mol%, have been successfully prepared by conventional melt-quenching technique. The physical and elastic properties of the glasses have been investigated using pulse echo technique. The longitudinal and shear velocity of the glasses were measured using the MBS8000 ultrasonic data acquisition system at 10 MHz frequency in room temperature. The density, ultrasonic velocity and elastic moduli are found to be composition dependent and the correlation between the elastic moduli with the atomic packing density is discussed in detailed. The shielding parameters, mass attenuation coefficients, half value layers and exposure buildup factor (EBF) values have been computed using WinXCom program with the use of GP fitting method, and variation of shielding parameters are discussed for the effect of PbO addition into the glasses and photon energy. An increase in the density of the glasses results in a change in crosslink density. The sound velocity and elastic properties increased with PbO content and increase in Poisson's ratio trend suggests that the rigidity of the glasses has decreased. Besides, the replacement of ZnO by PbO causes an increase in mass attenuation coefficient, while the half value layer and the exposure buildup factor were decreased and these glasses has been potentially used as shielding material.

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Comprehensive study on physical, elastic and shielding properties of lead zinc phosphate glasses

Binary (1 − x)(TeO2) − x(PbO), x = 0, 0.10, 0.15, 0.20, 0.25, 0.30 mol% glass system was fabricated using melt quenching method. X-ray diffraction (XRD) technique was employed to confirm the amorphous nature. The microanalysis of the major components was performed using energy dispersive EDX and X-ray spectrometry. Both the molar volume and the density were measured. FTIR and UV spectra were recorded at 400–4000 cm–1 and 220–800 nm, respectively. The optical band gap (Eopt), Urbach’s energy (Eu), index of refraction (n) were calculated using absorption spectrum fitting (ASF) and derivation of absorption spectrum fitting (DASF) methods. Molar refraction Rm and molecular polarizability α m have been calculated according to (ASF) method.

Effect of PbO on Optical Properties of Tellurite Glass

Samarium phosphate glasses in the composition range 5 mol% to 25 mol% Sm2O3 have been prepared. Raman spectra have been characterized in terms of structural components and their resemblance to those of other phosphate glasses shows that the samarium-modified glasses have similar structural features to those of other vitreous phosphates. The compositional dependences of the elastic constants and their hydrostatic pressure derivatives have been measured at room temperature. An increase in samarium content in a decrease of both C11 and the bulk modulus, Bs, to minimum values at a composition of about 20 mol% Sm2O3. Both C11 and C44 decrease with application of hydrostatic pressure: these glasses become easier to compress as pressure is increased. Such acoustic mode softening behaviour is not typical of other phosphate glasses. Visual examination in a diamond cell up to about 100 kbar does not reveal a structural or valence change associated with this vibrational instability. The vibrational anharmonicity and the pressure induced acoustic mode softening are discussed in terms of the Gruneisen approach. It is concluded that the anomalous elastic behaviour under pressure may arise from valence instability of the samarium ions.

H. A. A. Sidek

Papers

Synthesis and optical properties of ZnO-TeO2 glass system

Optical basicity and electronic polarizability of zinc borotellurite glass doped La3+ ions

Comprehensive study on physical, elastic and shielding properties of lead zinc phosphate glasses

Effect of PbO on Optical Properties of Tellurite Glass

Vibrational properties of samarium phosphate glasses