Udayraj C. Yadav; Yuvraj S. Malghe
Abstract
Nanosized barium cerate (BaCeO3) was prepared from barium cerium oxalate (BCO) precursor. Thermal decomposition of BCO precursor was studied using thermogravimetry(TG), differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques. BCO precursor ...
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Nanosized barium cerate (BaCeO3) was prepared from barium cerium oxalate (BCO) precursor. Thermal decomposition of BCO precursor was studied using thermogravimetry(TG), differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques. BCO precursor calcined at 1000°C for 2h gives nanosized BaCeO3 powder. Band gap of BaCeO3 was estimated using diffuse reflectance spectrophotometry and is found to be2.17 eV. Particle size distribution study reveals that particle size of BaCeO3varies between 10-70 nm. Dielectric behavior of BaCeO3 was studied with varying the temperature at different frequencies. BaCeO3 shows good dielectric and conductivity response. Copyright © 2017 VBRI Press.
Samy K. K. Shaat; Hussein A. Dawoud
Abstract
Our novelty for the presented work is to find a simple method to study electric and dielectric properties for samples such as magnetic materials. We focus on prepare and characterize of the ferrites. During the AC measurements, we struggled to use the Lissajous figure. In addition, we have a shortage ...
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Our novelty for the presented work is to find a simple method to study electric and dielectric properties for samples such as magnetic materials. We focus on prepare and characterize of the ferrites. During the AC measurements, we struggled to use the Lissajous figure. In addition, we have a shortage of equipment for measurements. This prompted us to look for a method to be easy to use with simple devices. The Delay-Time measurement method for any two different sinusoidal waves was used to calculate the phase shift ( ) between them using an oscilloscope. The was exercised to resolve the series and the parallel of RC in AC circuit. The phasor diagram of the series and the parallel of RC in AC circuit were plotted. All the main and derived quantities of the AC circuit were calculated, such as the immittances, conductivity and dielectric parameters. The presented method is considered as a simple method comparing to other methods. Thus, it can be replaced the other methods as well as it can be used from the scientists and engineers. Our Master students already used this method and they got good results. This paper is considered to be a preliminary analysis for this simple method and we will develop it. Copyright © 2017 VBRI Press.
Pragya Pandit; Pargin Bangotra
Abstract
In this paper we investigate the effect of lanthanum doping on structural, dielectric and electrical properties of lead magnesium niobate - lead titanate, 0.65Pb(Mg1/3Nb2/3O3)- 0.35PbTiO3 (x=0, 0.02, 0.05) ferroelectric ceramics. Dielectric and AC impedance spectroscopic measurements were ...
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In this paper we investigate the effect of lanthanum doping on structural, dielectric and electrical properties of lead magnesium niobate - lead titanate, 0.65Pb(Mg1/3Nb2/3O3)- 0.35PbTiO3 (x=0, 0.02, 0.05) ferroelectric ceramics. Dielectric and AC impedance spectroscopic measurements were carried out on pure and lanthanum doped PMN/PT ceramics over a wide temperature (30o- 450o C) and frequency interval (10 Hz-1 MHz). Pure and lanthanum doped Pb1-xLax[(Mg1+x/3Nb2-x/3)0.65Ti0.35(1-x/4)]O3, (x=0, 0.02, 0.05) ceramics were prepared by solid state reaction route using columbite precursor method. X-ray diffraction revealed tetragonal (P4mm) phase for pure PMN/PT ceramics and transition to pseudo cubic phase (Pm3m) was observed with increased lanthanum doping. The dielectric response of the lanthanum modified PMN/PT ceramics was interpreted in terms of modified curie weiss law. Modulus spectroscopy revealed the deviation of dielectric behavior from ideal Debye behaviour. Activation energies calculated from dielectric relaxation and modulus spectroscopy suggested that charge transport processes are due to oxygen ion hopping.The AC conductivity of the PMN/PT ceramics initially increased for 2 mol% of lanthanum doping followed by a subsequent decrease with further 5 mol% of lanthanum doping. The value of the activation energies calculated from the temperature dependance of ac conductivity was in the range from 1.20-1.48 ev which is due to doubly ionized oxygen vacancies. The overall structural, electrical and dielectric behaviour of Pb1-xLax[(Mg1+x/3Nb2-x/3)0.65Ti0.35(1-x/4)]O3, (x=0, 0.02, 0.05) ceramics is correlated to the relaxor nature induced by lanthanum doping.
Sathosh K. Kurni; Pradip Paik
Abstract
SiO2 nanoparticles of average size 15-20 nm have been synthesized and its dielectric properties have been investigated as a function of frequency (between 20 Hz to 2 MHz). A very high dielectric constant of ca. 14000 at 20 Hz and at room temperature has been observed which is very high compared to the ...
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SiO2 nanoparticles of average size 15-20 nm have been synthesized and its dielectric properties have been investigated as a function of frequency (between 20 Hz to 2 MHz). A very high dielectric constant of ca. 14000 at 20 Hz and at room temperature has been observed which is very high compared to the conventional bulk SiO2 particles (ca. 50-100). For this new SiO2 the loss value is found to be less than 1. These SiO2 nanoparticles with high dielectric constant and low loss can be offered its use in constructing high efficient electronic circuit boards and storage devices. Spectra between real and imaginary parts of dielectric constant reveal an inclined line with depressed semicircle. Impedance measurements have been performed to know the electrical properties of the novel SiO2 nanoparticles. XRD, TEM and FTIR characterizations confirm the solid state network structural, morphological shape and size, and chemical functionality of SiO2 respectively. Copyright © 2016 VBRI Press
