scholarly journals Study of Impedance Spectroscopy of Ferroelectric (Pb Sr)TiO3 Glass Ceramic System with Addition of La2O3

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
C. R. Gautam ◽  
D. Kumar ◽  
Prabhakar Singh ◽  
O. Parkash
Keyword(s):  
Impedance Spectroscopy ◽  
Glass Ceramic ◽  
Complex Modulus ◽  
Glassy Matrix ◽  
Treatment Schedule ◽  
Spectroscopic Techniques ◽  
Frequency Range ◽  
Ceramic System ◽  
Ceramic Samples ◽  
Spectroscopy Studies

Various composition of glasses were prepared by melt-quenched method in the glass ceramic system 64[(PbxSr1-x)⋅OTiO2]-25[(2SiO2⋅B2O3)]-7[BaO]-3[K2O] doped with 1 mole % La2O3 (0.0≤x≤0.4). Solid solution of perovskite lead strontium titanate (PST) phase was crystallized in borosilicate glassy matrix with controlled heat treatment schedule. X-ray diffraction analysis of these glass ceramic samples revealed that major crystalline phase of the entire glass ceramic samples bears cubic structure similar to SrTiO3 ceramic. Impedance spectroscopy studies were done in the frequency range 0.01 Hz to 3.0 MHz and in the temperature range 50 to 275°C. Impedance and complex modulus spectroscopic techniques were used to find out the various contributions to the polarization process. Resistive and capacitive contributions of the processes relaxing in the highest frequency range were found to have low values in comparison to the resistive and capacitive contributions for the processes relaxing in lower and intermediate frequencies ranges.

scholarly journals Dielectric Properties of La2O3 Doped Composite (PbxSr1−x)TiO3 Borosilicate Glass Ceramic

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
C. R. Gautam ◽  
Devendra Kumar ◽  
Om Parkash ◽  
O. P. Thakur
Keyword(s):  
Dielectric Constant ◽  
Glass Ceramic ◽  
Perovskite Phase ◽  
Glass Ceramics ◽  
Dielectric Behavior ◽  
Effective Dielectric Constant ◽  
Glassy Matrix ◽  
Crystal Glass ◽  
Treatment Schedule ◽  
Ceramic Samples

Ferroelectric (PbxSr1−x)TiO3 (PST) perovskite phase has been crystallized in borosilicate glassy matrix with a suitable choice of composition and heat treatment schedule. La2O3 is a donor dopant for PST and can make it semiconducting. Dispersion of semiconducting perovskite phase in insulating glassy matrix in glass-ceramic samples may lead to the formation of space charge polarization around crystal-glass interface, leading to a high value of effective dielectric constant, εr. Therefore, with the aim of the developing glass ceramics with high dielectric constant, glasses in the system 64[(PbxSr1−x)O·TiO2]-25[2SiO2·B2O3]-5[K2O]-5[BaO]-1[La2O3] have been prepared (0.5≤x≤1). It is found that the addition of La2O3 strongly affected the crystallization and dielectric behavior of glass-ceramic with PST perovskite phase. All glass ceramic samples show a diffuse broad Curie peak in their εr versus T plots. Curie peak temperature, Tc, depends on compositions of the glass-ceramic samples as well as frequency of measurements.

scholarly journals Synthesis, Crystallization, and Dielectric Behaviour of Lead Bismuth Titanate Borosilicate Glasses with Addition of 1% La2O3

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
C. R. Gautam ◽  
Abhishek Madheshiya ◽  
R. K. Dwivedi
Keyword(s):  
Glass Ceramic ◽  
Bismuth Titanate ◽  
Glass System ◽  
Glassy Matrix ◽  
Borosilicate Glasses ◽  
X Ray Diffraction ◽  
Mole Percent ◽  
Ceramic Samples ◽  
Donor Dopant ◽  
Quench Method

Lead bismuth titanate borosilicate glasses were prepared in the glass system 65[(PbxBi1-x)·TiO3]-34[2SiO2·B2O3]-1La2O3 (0.0≤x≤1.0) doped with one mole percent of La2O3 via conventional melt quench method. The amorphous nature of glass samples in this glass system is confirmed by using X-ray diffraction (XRD) study. Differential thermal analysis (DTA) has been employed to determine the glass transition temperature, Tg, as well as crystallization temperature, Tc. DTA measurements were recorded in temperature range from 30 to 1200°C. The prepared glasses were crystallized by regulated controlled heat treatment process on the basis of their DTA results. These samples are carried out for XRD measurements in the 2θ range from 20 to 80° to study the crystallization behaviour and phase formation of the glass ceramic samples. The scanning electron microscopy (SEM) of these glass ceramic samples has been carried out to explore the morphology through nucleation and growth of the crystallites in the glassy matrix. The values of dielectric constant as well as dielectric loss were increased with increasing the temperature within the frequency range from 20 Hz to 100 Hz. The addition of 1 mol% of La2O3 to the lead bismuth titanate glasses enhances the crystallization and acts as donor dopant for this glass system.

scholarly journals Impedance Spectroscopy (BeO+TiO2)-Ceramics with Additive of TiO2 Nanoparticles

2019 ◽  
pp. 366-380
Author(s):  
Anatoliy A. Lepeshev ◽  
Alexandr V. Pavlov ◽  
Nikolai A. Drokin
Keyword(s):  
Impedance Spectroscopy ◽  
High Frequency ◽  
Microwave Field ◽  
Frequency Range ◽  
Nanocrystalline Tio2 ◽  
Electrically Conductive ◽  
Dielectric Characteristics ◽  
Ceramic Samples ◽  
Static Resistance ◽  
First Time

The present study is aimed at obtaining electrically conductive two-component ceramics based on BeO with the addition of micro and nanocrystalline TiO2 powder. The ceramics of the composition (BeO+TiO2) is used in radio-electronic equipment as effective absorbers of microwave radiation and in other areas of modern electronics. The nature of the appearance of electrical conductivity and absorption of the microwave field in (BeO+TiO2) ceramics has not been completely established. The impedance spectroscopy method for the first time investigated the electrical and dielectric characteristics of this ceramics in the frequency range from 100 Hz to 100 MHz, depending on the presence of micro and nano-sized TiO2 phases in the composition of the BeO ceramics. It was established that the static resistance of ceramics with the addition of titanium oxide nanopowder is significantly reduced compared with the resistance of the original ceramics with TiO2 micropowder. It is shown that the real and imaginary components of the dielectric constant of the studied ceramics increase to abnormally large values when the frequency of the effective electric field decreases, and in the high frequency range f ≥ 108 Hz, the process of dielectric relaxation begins, leading to an increase in the dielectric loss tangent. The dielectric characteristics of these ceramic samples under conditions of blocking through conduction are determined

INCOMMENSURATE CRYSTAL GROWTH BEHAVIOR IN STRONTIUM TITANATE GLASS CERAMIC SYSTEM

2002 ◽  
Vol 16 (27) ◽  
pp. 1037-1047 ◽  
Author(s):  
O. P. THAKUR ◽  
DEVENDRA KUMAR ◽  
OM PARKASH ◽  
LAKSHMAN PANDEY
Keyword(s):  
Strontium Titanate ◽  
Glass Ceramic ◽  
Icosahedral Symmetry ◽  
Treatment Schedule ◽  
X Ray Diffraction ◽  
Ceramic System ◽  
Electron Microscopic ◽  
X Ray ◽  
Oxide Addition ◽  
Diffraction Patterns

Crystals with different faceting behavior were observed in the strontium titanate borosilicate glass ceramic system with a small amount of bismuth oxide addition and proper heat treatment schedule. These types of faceting morphology were generally observed in phase-separated glasses followed by heterogeneous nucleation. X-ray diffraction and electron microscopic techniques were used to characterize these samples. X-ray diffraction patterns for bulk and pulverized samples were observed to be readily different from each other. Peaks in the X-ray diffraction pattern for bulk samples can be indexed for icosahedral symmetry.

scholarly journals Study of PbTiO3-Based Glass Ceramics Containing SiO2

ISRN Ceramics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
V. K. Deshpande ◽  
V. U. Rahangdale
Keyword(s):  
Dielectric Constant ◽  
Glass Ceramic ◽  
Lead Titanate ◽  
Glass Ceramics ◽  
Treatment Schedule ◽  
Glass Ceramic Sample ◽  
Practical Applications ◽  
Ceramic Samples ◽  
Heat Treatment Schedule ◽  
Stage Heat Treatment

Glass samples with composition 50PbO : 25TiO2 : (25-X) B2O3 : XSiO2 (with X = 0, 1.5, 2.5, 3.5, and 5 mol%) were prepared by conventional quenching technique. These glass samples were converted to glass ceramics by the two-stage heat treatment schedule. Formation of ferroelectric lead titanate phase in the glass ceramics was confirmed from the XRD. The density, CTE, and dielectric constant of the glass and glass-ceramic samples were measured. The glass-ceramic sample containing 2.5 mol% SiO2 exhibited the highest dielectric constant. The SEMs of glass-ceramic samples were studied. The P-E hysteresis loop studies also revealed the highest remnant polarization for this sample, which has a potential for being developed for practical applications.

Conductivity Studies of Schiff Base Ligands Derived from O-Phenylenediamine and Their Co(II) and Zn(II) Complexes

2015 ◽  
Vol 12 (2) ◽  
pp. 13
Author(s):  
Muhamad Faridz Osman ◽  
Karimah Kassim
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Schiff Base ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Impedance Spectroscopy ◽  
Ftir Spectroscopy ◽  
Coordination Complexes ◽  
Frequency Range ◽  
Schiff Base Ligands

The coordination complexes of Co(II) and Zn(II) with Schiff bases derived from o-phenylenediamine and substituted 2-hydroxybenzaldehyde were prepared All compounds were characterized by Fourier transform infrared (FTIR) spectroscopy and Nuclear magnetic resonance (NMR) spectroscopy elemental analyzers. They were analyzed using impedance spectroscopy in the frequency range of 100Hz-1 MHz. LI and L2 showed higher conductivity compared to their metal complexes, which had values of 1.3 7 x 10-7 and 6.13 x 10-8 S/cm respectively. 

scholarly journals Dual-mode humidity detection using a lanthanide-based metal–organic framework: towards multifunctional humidity sensors

2017 ◽  
Vol 53 (32) ◽  
pp. 4465-4468 ◽  
Author(s):  
Yuan Gao ◽  
Pengtao Jing ◽  
Ning Yan ◽  
Michiel Hilbers ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Humidity Sensor ◽  
Metal Organic Framework ◽  
Dual Mode ◽  
Humidity Sensors ◽  
Highly Effective ◽  
Metal Organic ◽  
Spectroscopy Studies ◽  
Organic Framework

Combined photoluminescence and impedance spectroscopy studies show that a europium-based metal–organic framework behaves as a highly effective and reliable humidity sensor, enabling dual-mode humidity detection.

scholarly journals Towards Higher Electric Conductivity and Wider Phase Stability Range via Nanostructured Glass-Ceramics Processing

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1321
Author(s):  
Tomasz K. Pietrzak ◽  
Marek Wasiucionek ◽  
Jerzy E. Garbarczyk
Keyword(s):  
Glass Ceramic ◽  
Electronic Conductivity ◽  
Glass Ceramics ◽  
Temperature Stability ◽  
Ceramic Materials ◽  
Glassy Matrix ◽  
Oxide Glasses ◽  
Thermal Transitions ◽  
Stability Range ◽  
Conductivity Enhancement

This review article presents recent studies on nanostructured glass-ceramic materials with substantially improved electrical (ionic or electronic) conductivity or with an extended temperature stability range of highly conducting high-temperature crystalline phases. Such materials were synthesized by the thermal nanocrystallization of selected electrically conducting oxide glasses. Various nanostructured systems have been described, including glass-ceramics based on ion conductive glasses (silver iodate and bismuth oxide ones) and electronic conductive glasses (vanadate-phosphate and olivine-like ones). Most systems under consideration have been studied with the practical aim of using them as electrode or solid electrolyte materials for rechargeable Li-ion, Na-ion, all-solid batteries, or solid oxide fuel cells. It has been shown that the conductivity enhancement of glass-ceramics is closely correlated with their dual microstructure, consisting of nanocrystallites (5–100 nm) confined in the glassy matrix. The disordered interfacial regions in those materials form “easy conduction” paths. It has also been shown that the glassy matrices may be a suitable environment for phases, which in bulk form are stable at high temperatures, and may exist when confined in nanograins embedded in the glassy matrix even at room temperature. Many complementary experimental techniques probing the electrical conductivity, long- and short-range structure, microstructure at the nanometer scale, or thermal transitions have been used to characterize the glass-ceramic systems under consideration. Their results have helped to explain the correlations between the microstructure and the properties of these systems.

Dielectric and impedance spectroscopy studies of Ba0.90Y0.10SnO3

2020 ◽  
Author(s):  
Upendra Kumar ◽  
Dharmendra Yadav ◽  
Gurudeo Nirala ◽  
Shail Upadhyay ◽  
Epsita Kar ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Spectroscopy Studies
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