18 results on '"Deshpande, V. K."'
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2. Effect of Li 2 O-B 2 O 3 - SiO 2 - Nb 2 O 5 glass addition on dielectric and ferroelectric properties of Lithium Niobate ceramics.
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Deshpande, V. K. and Jagdale, M. V.
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DIELECTRIC properties of ferroelectric ceramic materials , *LITHIUM niobate , *SINTERING , *SOLID-state phase transformations , *DIELECTRIC properties , *PHYSIOLOGY - Abstract
LiNbO3has been synthesized by solid state sintering technique. The glass 30Li2O: 50B2O3: 10 Nb2O5: 10SiO2has been synthesized by conventional quenching technique. Different weight percentage of glass was added into LiNbO3ceramics and sintered at different temperatures. The samples were characterized by using X-Ray Diffraction, Density and Scanning Electron Microscope. The dielectric and ferroelectric measurements of these ceramics suggests that the addition of glass has helped in improving its properties. The LiNbO3ceramic with 5 wt% glass addition has shown optimum properties among the ceramics prepared. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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3. Study of Physical Properties of PbTiO 3 Based Glass-ceramic with Variation of Heat Treatment Duration.
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Rahangdale, V. U. and Deshpande, V. K.
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LEAD titanate , *PROPERTIES of matter , *GLASS-ceramics , *HEAT treatment of metals , *IMPEDANCE spectroscopy , *FERROELECTRIC crystals - Abstract
PbTiO3glass-ceramics were prepared by following two stage heat treatment schedule. The effect of heat treatment duration on the physical properties of glass-ceramic was studied. The density, CTE, dielectric constant and ferroelectric properties varied systematically with heat treatment duration and exhibited an optimum for 32 h. These properties have a good correlation with the volume fraction of lead titanate phase crystallized in the glass-ceramics. Impedance spectroscopy was used to analyse the behaviour of glass-ceramic samples. The studies of ferroelectric properties show that PbTiO3glass-ceramics has a potential for high temperature applications. [ABSTRACT FROM PUBLISHER]
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- 2014
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4. Study of PbO - TiO2 - B2O3 Glass and Glass Ceramics.
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Shankar, J. and Deshpande, V. K.
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LEAD oxides , *TITANIUM dioxide , *BARIUM oxide , *METALLIC glasses , *GLASS-ceramics , *METAL quenching - Abstract
Glass samples with composition (35 - X) B2O3 - (40 + X) PbO - 25 TiO2 (where X = 0, 2.5, 5, 7.5 and 10 mol %) were prepared using conventional quenching technique. It was observed that as PbO content increases the value of Tcand Tc decreases. These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The density values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and CTE results of the glass-ceramics. The XRD results revealed the formation of tetragonal lead titanate as a major crystalline phase in the glass ceramics. The dielectric constant of glass ceramic samples is higher than those of corresponding glasses [ABSTRACT FROM AUTHOR]
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- 2015
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5. Effect of CaO Addition on the Properties of PbTiO 3 Glass Ceramic.
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Shankar, J. and Deshpande, V. K.
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ADDITION reactions , *LIME (Minerals) , *TITANATES , *GLASS-ceramics , *METAL quenching , *METALLIC glasses , *CHEMICAL sample preparation , *HEAT treatment of metals , *X-ray diffraction - Abstract
Glasses of compositions (50 -X) PbO-X CaO-25 TiO2-25 B2O3 (where X = 0,5,10 and 15 mol%) were prepared by conventional quenching technique. The glass samples were converted to glass ceramics by two stage heat treatment schedule. The XRD results confirmed the formation of ferroelectric PbTiO3 as a major phase in the glass ceramics. For all the CaO added samples the dielectric constant as a function of temperature, exhibit a peak around 475°C, which is close to the Curie temperature of PbTiO3. The hysteresis measurement supports the ferroelectric nature of the glass ceramics. [ABSTRACT FROM PUBLISHER]
- Published
- 2011
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6. Study of Lead Titanate Based Glass Ceramics with Addition of BaO.
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Shankar, J. and Deshpande, V. K.
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GLASS-ceramics , *CRYSTALLIZATION , *GLASS transition temperature , *FERROELECTRICITY , *HYSTERESIS , *TITANATES , *BARIUM - Abstract
Glass samples with composition of (50-X) PbO-X BaO-25 TiO2-25B2O3 (where X = 0, 5, 10 and 15 mol%) were prepared using conventional quenching technique. The amorphous nature of glass samples were confirmed by XRD. The glass transition temperature, Tg and crystallization temperature Tc were determined from the DTA. It has been observed that the addition of BaO enhances the Tg and reduces the Tc. These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The glass ceramic samples were characterized by XRD, SEM and dielectric constant measurements. The dielectric constant for all the glass ceramic samples was observed to be higher than that of corresponding glass samples. Further, with addition of BaO the dielectric constant for glass ceramic samples increases up to 10 mol% of BaO and beyond this concentration it decreases. The XRD results revealed the formation of ferroelectric Lead Titanate as a major crystalline phase in the glass ceramics. This is supported by the SEM results which show rounded crystallites of lead titanate. This explains the enhancement in the dielectric constant. The addition of BaO to the glass contributes to the formation of BaB2O4 and Barium-Titanium-Borate (BTB) phases. Additional phases observed in these glasses include PbB2O4 and PbB2O7. This has been supported by SEM results indicating needle-like crystals in glass ceramic samples containing higher concentration of BaO. The observed hysteresis (P vs. E) loop at room temperature confirmed the ferroelectric nature of these glass ceramics. [ABSTRACT FROM AUTHOR]
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- 2010
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7. Effect of Heat Treatment Schedule on the Properties of Lead Titanate Based Glass Ceramic.
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Deshpande, V. K. and Shankar, J.
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BUILDING material density , *CERAMICS , *INDUSTRIAL chemistry , *POTTERY , *HEATING equipment - Abstract
The lead titanate based glass samples were prepared by conventional quenching technique. The Tg, Tc and density of the glass samples were measured. The glass samples were converted to glass ceramics by two stage heat treatment schedule. The dielectric constant has been studied for the glass and glass ceramics. The glass ceramic sample obtained by optimized heat treatment schedule exhibited maximum density and dielectric constant due to precipitation of crystalline PbTiO3 phase. [ABSTRACT FROM AUTHOR]
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- 2009
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8. Enhancement in electrical conductivity of Li2O : B2O3: V2O5 glasses.
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Gedam, R. S. and Deshpande, V. K.
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NANOCRYSTALS , *ELECTRIC conductivity , *NANOPARTICLES , *NUCLEATION , *CRYSTALLIZATION , *PHYSICAL & theoretical chemistry - Abstract
The study of electrical conductivity of 30Li2O : (70 - x) B2O3: xV2O5 glass samples has been carried out. The results have been explained by dividing the temperature range into two regions. In region I, conductivity shows Arrhenius behaviour for all the samples. The conductivity increases with addition of V2O5. The results have been explained in the light of Anderson and Stuart Model. In region II, an anomalous enhancement in the conductivity is observed for all the samples up to certain temperature beyond which the conductivity decreases. The enhancement in the conductivity in the annealed glass sample has been attributed to nanocrystallization. [ABSTRACT FROM AUTHOR]
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- 2009
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9. PbTiO3 Based Ferroelectric Glass Ceramics.
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Shankar, J. and Deshpande, V. K.
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LEAD titanate , *FERROELECTRIC ceramics , *X-ray diffraction , *HYSTERESIS , *GLASS-ceramics , *FERROELECTRIC materials - Abstract
Glass samples with composition (50 - X) PbO - X MO - 25 TiO2 - 25B2O3 (where X = 0, 5, 10 and 15 mol % and M = Ba, Sr) were prepared using conventional quenching technique. It has been observed that the addition of MO to PbO - TiO2 - B2O3, enhances the Tg. The rise in Tg with MO content may be attributed to the greater field strength of M2+ cation which leads to the formation of stronger bonds. These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The XRD results revealed the formation of tetragonal lead titanate as a major crystalline phase in the glass ceramics. The addition of MO to the glass, contributes to the formation of secondary crystalline phases BaB2O4, Sr2B2O5. The ferroelectric nature of all the glass ceramic samples is confirmed by P - E hysteresis measurements. [ABSTRACT FROM AUTHOR]
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- 2014
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10. Effect of La2O3 on the electrical conductivity and thermal properties of proton conducting glasses.
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Tiple, S. R. and Deshpande, V. K.
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LANTHANUM , *ELECTRIC conductivity , *THERMAL properties , *PROTONS , *METALLIC glasses , *STABILITY (Mechanics) , *THERMAL expansion , *GLASS transition temperature - Abstract
The study of proton conducting glasses 30 BaO:5 SrO:65 P2O5 with addition of La2O3 has been carried out. The chemical durability of glass is found to increase with addition of La2O3 ensuring stability. The increase in density and glass transition temperature with addition of La2O3 indicate the stability of the glass. This is further supported by the observed decrease in Coefficient of Thermal Expansion (CTE) with addition of La2O3. [ABSTRACT FROM AUTHOR]
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- 2013
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11. Application of Dielectric Mixtures Formulae to PbTiO3 Based Glass-Ceramic Systems.
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Shankar, J., Rani, G. Neeraja, and Deshpande, V. K.
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GLASS-ceramics , *GLASS , *HEAT treatment , *PERMITTIVITY , *DIELECTRICS , *TRANSITION temperature , *THERMAL expansion - Abstract
Glass samples with composition (50 - X) PbO - (25 + X) TiO2 - 25 B2O3 (where X =0, 5, 10 and 12.5 mol %) were prepared using conventional quenching technique. These glass samples were converted to glass ceramics by following two stage heat treatment schedules. Transition temperature (Tg), crystallization temperature (Tc), density and Coefficient of Thermal Expansion (CTE) of glass and glass ceramic samples measured. Tg and Tc observed to decrease with increase in the content of TiO2. The density values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and CTE results of the glass–ceramics. The dielectric constant of glass ceramic samples is higher than those of corresponding glasses. Maxwell’s dielectric mixture formula was used to correlate the theoretically predicted values of dielectric constant with experimentally observed values. [ABSTRACT FROM AUTHOR]
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- 2019
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12. Study of microstructure and thermal properties of PbTiO3 based glass ceramics.
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Shankar, J., Raju, P., Kumar, A. Shiva, Anjaiah, J., Rani, G. Neeraja, Deshpande, V. K., Rani, G Neeraja, Anjaiah, J, and Raju, P
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GLASS-ceramics , *THERMAL properties , *LEAD titanate , *CERAMICS , *MICROSTRUCTURE , *HEAT treatment - Abstract
Glass samples with composition (35- X) B2O3 − (40 +X) PbO - 25 TiO2 (where X = 0, 2.5, 5, 7.5 and 10 mol %) were prepared using conventional quenching technique. These glass samples were converted to glass ceramics by following two stage heat treatment schedules. The density (ρ) values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and Coefficient of Thermal Expansion (CTE) results of the glass–ceramics. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate (PbTiO3) as a major crystalline phase and lead borate (PbB2O4) as minor crystalline phase. The microstructure of glass ceramic samples contains nano crystallites of lead titanate embedded in a borate glass matrix. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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13. Study of Microstructure and Dielectric Properties of PbTiO3 based Glass Ceramics.
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Shankar, J., Rani, G. Neeraja, Anjaiah, J., Raju, P., and Deshpande, V. K.
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GLASS-ceramics , *DIELECTRIC properties , *GLASS transition temperature , *LEAD titanate , *CERAMICS , *GLASS - Abstract
Glass samples with composition (35- X) B2O3 - (40 +X) PbO - 25 TiO2 (where X= 0, 2.5,5, 7.5 and 10 mol %) were prepared using conventional quenching technique. It was observed that as PbO content increases the values glass transition temperature (Tg) and crystallization temperature (Tc) decreases. The replacement of boron by a bigger Pb ion expands the network there by reducing the glass transition temperature (Tg). These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The density(ρ) values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and Coefficient of Thermal Expansion (CTE) results of the glass–ceramics. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate (PbTiO3) as a major crystalline phase and lead borate (PbB2O4) as minor crystalline phase. The microstructure of glass ceramic samples contains nano crystallites of lead titanate embedded in a borate glass matrix. As the content of glass former (B2O3) is reduced, the PbTiO3 crystals precipitated in glass matrix are observed to increase. The dielectric constant values of glass ceramic samples are higher than those of corresponding glass samples. [ABSTRACT FROM AUTHOR]
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- 2019
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14. Establishment of Normative data for Monaural Recordings of Auditory Brainstem Response and its Application in Screening Patients with Hearing Loss: A Cohort Study.
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CHALAK, SHIVAJI, KALE, ANITA, DESHPANDE, V. K., and BISWAS, D. A.
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NORMATIVE economics , *AUDITORY evoked response , *BRAIN stem , *VERTEBRAE , *RADIOLOGISTS , *ATLANTO-occipital joint - Abstract
Aim: The classic variants in superior articular facets of atlas such as, variability in shape, presence of notch, constrictions, partial or complete separation of facets, and presence of pressure facets, have been reported to a limited extent in relation to ergonomics of cranio-vertebral joint. Objective: The objectives of the present study were to report the analyzed morphological features and metrical values of superior articular facets of the atlas. The morphological features which were included in this study were variability in shapes, constrictions and partial or complete separation of facets. The metrical measure included the surface area measurement of the facets. Material and Methods: This study was carried out on 50 (100 sides) dry atlas vertebrae from the Department of Anatomy, St John's Medical College, Bangalore, India. The superior articular facets were studied for the shape and symmetry, constrictions and partial or complete separation of facets. The surface area of the facets were measured by using Image J (Image processing and analysis in JAVA) tool, that was primarily designed to measure and analyze different metrics. Results: The mean surface area on the right side was 157.3 ± 29.02, and on the left side, it was 158.5 ± 24.85. Oval, irregular, kidney and figure of eight shapes were observed either on both sides or on one side. Bilateral constrictions of facets were seen in 58 % of vertebrae. Bilateral, complete separations of facets were seen in 30% of vertebrae Conclusion: The observations of the present study are important to understand the ergonomics of the cranio-vertebral joint and they are helpful for academicians, neuro-surgeons, clinicians and radiologists in day to day clinical practice. [ABSTRACT FROM AUTHOR]
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- 2013
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15. Crystallization and dielectric properties of PbTiO3 based glass ceramics.
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Shankar, J., Rani, G. Neeraja, Deshpande, V. K., Singh, Biswas, and Das
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GLASS-ceramics synthesis , *QUENCHING (Chemistry) , *HEAT treatment , *LEAD titanate , *FERROELECTRIC crystals , *HYSTERESIS loop - Abstract
Glass samples with composition (50 - X) PbO - (25 + X) TiO2 - 25 B2O3 (where X = 0, 5, 10 and 12.5 mol %) were prepared using conventional quenching technique. These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate as a major crystalline phase. The SEM results show rounded crystallite of lead titanate. The ferroelectric nature of all the glass ceramic samples is confirmed by P - E hysteresis measurements. The extended heat treatment of glass ceramic samples at 593K for 10 h exhibited saturated hysteresis loops with higher values of remnant polarization. [ABSTRACT FROM AUTHOR]
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- 2018
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16. Synthesis and Characterization of PbTiO3 based Glass Ceramics.
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Shankar, J., Rani, G. Neeraja, Mamatha, B., and Deshpande, V. K.
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CERAMIC materials synthesis , *LEAD titanate , *METALLIC glasses , *METAL quenching , *HEAT treatment , *HYSTERESIS - Abstract
Glass samples with composition (50 - X) PbO - XCaO - 25 TiO2 - 25 B2O3 (where = 0, .5, 10 and 15 mol %) were prepared using conventional quenching technique. It was observed that with the addition of alkaline earth oxides to lead borate glass containing TiO2 alters the network (conversion of BO3 to BO4) increasing the rigidity of the glass which enhances the Tg. These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The density values of glass ceramic samples are higher than those of corresponding glass samples. It was observed that there was good correlation between the density and CTE results of the glass-ceramics. The XRD results in the glass ceramics revealed the formation of tetragonal lead titanate as a major crystalline phase and Ca3Ti2O7 as minor crystalline phase. The ferroelectric nature of all the glass ceramic samples is confirmed by P - E hysteresis measurements. [ABSTRACT FROM AUTHOR]
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- 2017
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17. SEED YIELD AND QUALITY OF BRINJAL AS INFLUENCED BY CROP NUTRITION.
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Kiran, J., Vyakaranahal, B. S., Raikar, S. D., Ravikumar, G. H., and Deshpande, V. K.
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EXPERIMENTS , *FERTILIZER research , *BIOFERTILIZERS , *MICRONUTRIENTS , *EGGPLANT , *AZOSPIRILLUM , *AGRICULTURAL chemicals , *PHOSPHATES , *GERMINATION , *SEEDLINGS - Abstract
An experiment was conducted during 2005-06 to study the effect of fertilizers, biofertilizers and micronutrients on plant growth, seed yield and quality of brinjal. The results indicated that, application of 100:100*:50 kg NPK per ha + Azospirillum + Phosphate solubilizing bacteria (PSB) each @ 125 g per ha (root dipping) along with zinc sulphate (0.2%) spray recorded significantly higher plant height (89.47 cm), number of branches (32), number of leaves (87), number of fruits (20), fruit yield (27.06 t/ha), number of seeds per fruit (1852), 1000-seed weight (7.90 g), seed yield (633 kg/ha), percentage of germination (97), field emergence (91), seedling vigour index (2024) and seedling dry weight (48.84 mg) over 125:100:50 Kg NPK / ha (RDF) at Dharwad conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2010
18. Dielectric and Ferroelectric Properties of Al2O3 Containing Lead Titanate Based Glass-ceramics.
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Rahangdale, V. U., Gala, D. K., Acharya, R. M., and Deshpande, V. K.
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FERROELECTRIC materials , *DIELECTRIC materials , *LEAD titanate , *CERAMICS , *ALUMINUM oxide , *QUENCHING (Chemistry) - Abstract
Glass Samples were prepared by conventional melt quenching technique. These glass samples were converted to glass-ceramics by following two stage heat treatment schedule. The density, dielectric constant and volume fraction of PbTiO3 in glass-ceramic samples have been observed to increase with Al2O3 addition. The observed increase in the above properties has been attributed to formation of tetragonal PbTiO3 phase in the glass-ceramics. All the glassceramic samples exhibited the ferroelectric hysteresis loop. The value of remnant polarization was observed to increase with Al2O3 addition. The enhancement in the values of remnant polarization may be attributed to increase in the volume fraction of PbTiO3 phase in glass-ceramics. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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