Study of the elastic properties of (PbO)x(P2O5)1−x lead phosphate glass using an ultrasonic technique (original) (raw)
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Lead based borate glass systems of binary PbO-B2O3 with different compositions are prepared by melt-quenching technique. Density of all the glass samples is measured using relative measurement method. The longitudinal and shear ultrasonic velocities are measured for all the compositions at 303 K and at 10 MHz frequencies using the Pulse Echo overlap method. Elastic moduli and other parameters such as molar volume, Poisson's ratio, acoustic impedance, microhardness, Debye and softening temperature and thermal expansion coefficient are calculated from density and velocity data, and they are used to gain knowledge about the structural and physical properties of these glasses and are correlated to the rigidity and compactness of the glass systems. The thermal stability of the glass samples is investigated by Thermo Gravimetric (TG) Analysis and it is used to measure the weight loss as the temperature of the sample is increased. Differential thermal analysis (DTA) is used to identify the glass transition temperature, crystallization temperature and melting temperature.
Physica B: Condensed Matter, 2009
Glasses in the system (95Àx) [0.25 Na 2 O-0.75 B 2 O 3 ]-x P 2 O 5-5 Fe 2 O 3 (0pxp15 mol%), have been prepared by the melt quenching technique. Elastic properties and FT-IR spectroscopic studies have been employed to study the role of P 2 O 5 on the structure of the glass system. Elastic properties Poisson's ratio, micro-hardness and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz (both longitudinal and shear) at room temperature. The results showed that the density and the molar volume increase as both sound velocities and the determined glass transition temperatures decrease with increasing the contents of P 2 O 5. Infrared spectra of the glasses reveal that the borate network consists of diborate units and is affected by the increase in the concentration of P 2 O 5 content as a second network former. These results are interpreted in terms of the replacement of the diborate units with B-O-B bridges by phosphate units with non-bridging oxygens (NBOs). Therefore, the elastic moduli are observed to decrease with the increase in P 2 O 5 content.
Advances in Materials Science and Engineering, 2015
Binary zinc phosphate glass system with composition of (ZnO) (P 2 O 5 ) 1− , (x = 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 mol%) was successfully prepared using a conventional melt-quenching method. Composition dependence of physical properties and elastic properties in the (ZnO) (P 2 O 5 ) 1− were discussed in association with the effects of adding zinc oxide (ZnO) as a modifier. The addition of ZnO modifier was expected to produce substantial changes on physical properties of the phosphate glasses. An increase in density values of the phosphate glasses was observed. Elastic moduli were studied by measuring ultrasonic longitudinal and shear velocities (V and V ) of the glasses at room. Longitudinal modulus, shear modulus, bulk modulus, Young's modulus, Poisson's ratio, and Debye temperature ( ) were derived from both data of velocities and respective density of all of the samples. Findings from present work showed dependence of density and elastic moduli of each ZnO-P 2 O 5 series on glass composition.
Formation and Elastic Behavior of Lead-Magnesium Chlorophosphate Glasses
A series of ternary lead-magnesium chlorophosphate glasses, (PbCl2)x(MgO)1−x(P2O5)0.4, of various compositions with 0.3 ≤ x ≤ 0.45 have been successfully prepared and their elastic properties have been characterized at room temperature. Results from the studies show that both the longitudinal and shear wave velocities decrease with increase of PbCl2 composition. The elastic constants C11, C44 and Young's modulus show a decreasing trend while the elastic constant C12, bulk modulus and Poisson's ratio show an increasing trend as the fraction of PbCl2 increases. This behavior of the elastic properties is related to the change in the structure of glasses as well as the interatomic bonding.
2018
Preparation of glass samples in the system, 10SrO – xPbO – (90-x)SGD, where SGD stands for deteriorated silica gel and x = 20, 25, 30, 35, 40 and 45 mol%, were prepared by a melted quenching technique at a temperature of 1250 °C. The Archimedes principle was used to measure density of the glass samples, and then these data were used to calculate their molar volumes. Ultrasonic velocities of this glass system were investigated using the pulse echo technique at room temperature. Both velocities and density of the system were further used to estimate the elastic moduli. The results showed that the concentration of PbO has an effect on the glass structure. The elastic moduli of the glass samples were varied by changing the concentration of PbO and its maximum appeared at 35 mol% of PbO. The structural properties of the glass samples were studied using FTIR spectroscopy, measuring in the range of 400-2000 cm-1. It was found that higher contents result in the breakdown of Si-O bonds and t...
Network structure of molybdenum lead phosphate glasses: Infrared spectra and constants of elasticity
Physica B: Condensed Matter, 2011
Molybdenum lead phosphate glasses doped with La 2 O 3 of the system xMoO 3 -5La 2 O 3 -50P 2 O 5 -(45 À x)PbO, with 0 r x r25 mol%, have been synthesized and studied by FTIR, ultrasonic and differential scanning calorimetry (DSC) in order to investigate the role of MoO 3 content on their atomic structure. The constants of elasticity and Debye temperatures of the glasses have been investigated using sound velocity measurements at 4 MHz. According to the IR analysis, the vibrations of the phosphate structural units are shifted towards higher wavenumbers associated with the formation of bridging oxygens. The change in density with MoO 3 content reveals that the molybdate units are less dense than the lead units. The observed compositional dependence of the constants of elasticity is interpreted in terms of the effect of MoO 3 on the different phosphate bonds. It is assumed that MoO 3 plays the role of a former by increasing the ultrasonic velocity and the constants of elasticity of the phosphate glasses.
Ultrasonic measurement and elastic properties of the PbO-SrO-B2O3 glass system
Revista IBRACON de Estruturas e Materiais, 2020
ABSTRACT: The PbO-SrO-B2O3 glass system with the of molar ratio of R (= PbO/B2O3) were prepared by fusion method. The elastic properties have been investigated using longitudinal and transversal ultrasonic wave velocity. Measurements were performed at room temperature and using pulse-echo technique at frequency of 5 MHz. The results indicate that, when increasing R value, the glass network stability decreases. This decrease indicates, of the increase the number of borate structures with non bridging oxygen (NBOs) at the expense of the decrease of borate units with tetrahedral structures. This feature may lead to the more open glass network structures and lower stiffness of the samples studied.
Studies of some mechanical and optical properties of: (70−x)TeO2+15B2O3+15P2O5+xLi2O glasses
Journal of Non-Crystalline Solids, 2008
Specimens of the glassy system: (70 À x)TeO 2 + 15B 2 O 3 + 15P 2 O 5 + xLi 2 O, where x = 5, 10, 15, 20, 25 and 30 mol% were prepared by the melt-quenching. An ultrasonic pulse-echo technique was employed, at 5 MHz, for measuring: the ultrasonic attenuation, longitudinal and shear wave velocities, elastic moduli, Poisson ratio, Debye temperature and hardness of the present glasses. It is found that the gradual replacement of TeO 2 by Li 2 O in the glass matrix up to 30 mol% leads to decrease the average crosslink density and rigidity of prepared samples which affects the properties, i.e., the hardness, ultrasonic wave velocities and elastic moduli are decreased, while the Poisson ratio and the ultrasonic attenuation are increased. Also, optical absorption spectra were recorded in the range, 200-800 nm for these glasses. The obtained results showed that a gradual shift in the fundamental absorption edge toward longer wavelengths occurred. Values of both of the optical energy gap, E opt , and width tails, DE, are determined. It is observed that E opt is decreased and DE increased with the increase of Li 2 O in the glass matrix up to 30 mol%. The compositional dependences of the above properties are discussed and correlated to the structure of tested glasses.
Structural and acoustical studies of lead sodium borate glasses
Journal of Alloys and Compounds, 2009
Glasses in the system Na 2−2x B 4−4x Pb x O 7−6x , 0 ≤ x ≤ 0.8, have been prepared by the melt quenching technique. Elastic properties and Debye temperature have been investigated using sound velocity measurements at 4 MHz. The ultrasonic parameters along with the IR spectroscopic studies have been employed to study the role of PbO on the structure of Na 2 B 4 O 7 glass. The density, the molar volume, and the ultrasonic parameters of these samples have been found to be compositional dependent. The results indicate that PbO acts as a network modifier in the range 0 ≤ x ≤ 0.4, while beyound x = 0.4, PbO acts as a network former which affects the diborate units that mainly consist the strong borate network. These results are interpreted in terms of the IR analysis that indicates the transformation of the structural units BO 3 into BO 4 , the increase in the number of non-bridging oxygen atoms, and the substitution of longer Pb O bond length, in place of shorter B O bond. The observed compositional dependence of the elastic moduli is interpreted in terms of the effect of PbO on the boron-coordination number of the glass structure and to the relatively large electron-phonon anharmonic interactions. A good correlation was observed between the experimentally determined elastic moduli and those computed according to Makishima-Mackenzie model.