Study the physical, electrical and dielectric properties of calcium doped Ni–Zn ferrites

2019 ◽  
Vol 33 (12) ◽  
pp. 1950145 ◽  
Author(s):  
M. A. A. Nooman ◽  
M. N. I. Khan ◽  
S. D. Hossain ◽  
M. F. Hossain ◽  
M. A. Samad ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Spinel Phase ◽  
Nominal Composition ◽  
Thermally Activated ◽  
Composition Formula ◽  
Zn Ferrite ◽  
Mobility Of Charge Carriers ◽  
Electrical And Dielectric Properties ◽  
Calcium Doped

Calcium doped Ni–Zn ferrites having the nominal composition [Formula: see text] (x = 0, 0.1, 0.2, 0.3 and 0.4) are prepared via the conventional ceramic method at [Formula: see text] for 3 h to study their physical, electrical and dielectric properties at high frequencies which have extended their applications. The X-ray diffraction (XRD) and scanning electron microscope (SEM) have been used to characterize the microstructure and surface morphology of the prepared composition. XRD patterns reveal the formation of pure spinel phase ferrites whereas SEM micrographs display nonhomogeneous grains of polyhedral shape. The studies disclose that with increasing Ca content in spinel, the lattice parameter of the Ni–Zn ferrite increases and at the same time the grain boundary also increases. As a result of the increased boundary, the large grains could be trapped pores inside the grains which have affected the density, resistivity and dielectric constant of the sample. The DC electrical resistivity of the prepared sample decreases with the increase of Ca content. Also, the resistivity decreases with increasing the temperature. This increase in the conductivity with temperature must be regarded mainly as due to the thermally activated mobility of charge carriers, but not to a thermally activated creation of these carriers. The dielectric constant decreases with the increasing frequency following the Verway-de-Boer hopping mechanism.

Structure and microwave dielectric properties of (Zn1−xNix)TiO3 ceramics

2003 ◽  
Vol 18 (5) ◽  
pp. 1067-1072 ◽  
Author(s):  
Hyo Tae Kim ◽  
Joon-Cheol Hwang ◽  
Joong-Hee Nam ◽  
Byung Hyun Choi ◽  
Michael T. Lanagan
Keyword(s):  
Dielectric Constant ◽  
Phase Composition ◽  
Dielectric Properties ◽  
Phase Distribution ◽  
Spinel Phase ◽  
Measurement Techniques ◽  
Microwave Dielectric Properties ◽  
Rutile Phase ◽  
Microwave Measurement ◽  
Microwave Dielectric

Dielectric ceramics in the system (Zn1−xNix)TiO3, x = 0 to 1 were synthesized by the solid-state reaction route. The phase distribution, microstructure, and dielectric properties were characterized using powder x-ray diffraction analysis, electron microscopy, and microwave measurement techniques. Three phase composition regions were identified in the specimens sintered at 1150 °C: [spinel + rutile] at 0 ≤ x ≤ 0.5, [spinel + ilmenite + rutile] at 0.5 < x ≤ 0.8, and [ilmenite] phase at 0.8 < x ≤ 1. For the 0 ≤ x ≤ 0.5 region, the amount of Ti-rich precipitates incorporated into the spinel phase decreased with the Ni content at 0 ≤ x ≤ 0.5, with a concomitant increase of the rutile phase. The microwave dielectric properties depended on the phase composition and volume according to the three typical phase regions, where the relative amount of rutile to the spinel or ilmenite determined the dielectric properties. The dielectric constant as a function of Ni addition was modeled with a Maxwell mixing rule. An optimum phase distribution was determined in this system with dielectric constant of 22, a Q × f of 60,000, and a low temperature coefficient of the resonant frequency.

Comparative Study on Electrical and Dielectric Properties of Sintered Nano and Micro Silicon Nitride Ceramics

2016 ◽  
Vol 2 (1) ◽  
pp. 13-18
Author(s):  
Imran Khan ◽  
M S A Khan
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Silicon Nitride ◽  
Dc Conductivity ◽  
Temperature Range ◽  
Nitride Ceramics ◽  
Electrical And Dielectric Properties ◽  
Sintered Silicon

In the present work we have studied the electrical conductivity, dielectric constant and dielectric loss of Sintered Silicon Nitride ceramics. In this study it was found that the grain size has great impact on electrical conductivity and dielectric properties of Sintered Silicon Nitride Ceramics. The result shows more efficiency of electrical and dielectric properties with nano sized grains.  The sintering was performed in a programmable furnace at 950 K. The dc conductivity measured in the temperature range 300 K to 900 K. At higher temperature (T > 800 K), the dc conductivity increases exponentially with temperature for both of the investigated samples. Dielectric constant and loss are measured in the temperature range 300 K to 900 K with frequency range 1 KHz to 1 MHz. To confirm the grain size, the samples are characterized by the Scanning Electron Microscope (SEM). These types of samples can be used as a high temperature semi-conducting materials.

Dielectric properties of Ba0.97Bi0.02TiO3–Ba1−xMgxSn0.02Ti0.98O3 composite ceramics

2016 ◽  
Vol 30 (29) ◽  
pp. 1650363
Author(s):  
Jing wang ◽  
Guijuan Rong ◽  
Liangbin Hao ◽  
Lan Gao ◽  
Haiyan Cheng ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Breakdown Strength ◽  
Dielectric Strength ◽  
Dielectric Behavior ◽  
Composite Ceramics ◽  
Solid State Method ◽  
Composition Formula ◽  
State Method ◽  
Mg Content

A wet solid-state method was used in this work to produce [Formula: see text]–[Formula: see text] materials. By using core-shell structure nanocubic [Formula: see text] (BMST) decorated [Formula: see text] (BBT) assemblies, a composite capacitor with improved dielectric constant and enhanced breakdown strength was successfully fabricated in contrast with the composite ferroelectric [Formula: see text]–[Formula: see text] (BBT–BST) ceramic. With increasing Mg content, the ceramic capacitors display a stronger performance in its dielectric behavior. The best dielectric properties were obtained in the composition [Formula: see text] = 0.007 with the dielectric constant above 65,000. The dielectric strength of the ceramics was measured by a withstanding voltage tester. The best dielectric strength was achieved in the composition [Formula: see text] = 0.007 with [Formula: see text] = 5.455 kV/mm.

scholarly journals Porous and Nonporous Film-Shaped Magnetorheological Nanocomposites: Dielectric and Electrical Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Aref Naimzad ◽  
Yousef Hojjat ◽  
Mojtaba Ghodsi
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Volume Resistivity ◽  
Comparative Investigation ◽  
Dielectric Constants ◽  
Dielectric Losses ◽  
Iron Particles ◽  
Electrical And Dielectric Properties

This paper presents a brief experimental comparative study on electrical and dielectric properties of two sets of porous and nonporous MRNCs, each including five samples of film-shaped magnetorheological nanocomposites (MRNCs) based on room temperature vulcanized (RTV) silicone rubber and nanosized carbonyl iron particles (CIPs). The electrical and dielectric properties of porous and nonporous MRNCs were measured at five different filler concentrations. Several experiments were performed to measure the volume resistivity, dielectric constant, and dielectric loss. The MRNCs dielectric properties were analysed with respect to the parameters like frequency and CIPs loadings. The electrical conductivity was studied in terms of volume resistivity. The comparative investigation suggests the porous MRNCs for smart and light-weighted structures those benefits from a lower electrical property, dielectric losses, and dielectric constants.

scholarly journals Synthesis and Study of Structural and Dielectric Properties of Dy-Ho Doped Mn-Zn Ferrite Nanoparticles

2021 ◽  
Author(s):  
Krishtappa Manjunatha ◽  
Veerabhadrappa Jagadeesha Angadi ◽  
Brian Jeevan Fernandes ◽  
Keralapura Parthasarathy Ramesh
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Ac Conductivity ◽  
Ferrite Nanoparticles ◽  
The Real ◽  
Low Dielectric ◽  
Zn Ferrite ◽  
Xrd Patterns ◽  
The One

The Dy-Ho doped Mn-Zn Ferrite nanoparticles have been synthesized by solution combustion method using mixture of fuels as glucose and urea. The synthesized samples of structural properties were characterized through XRD (X-ray diffraction) and dielectric properties were studied through impedance analyzer. The XRD patterns of all samples confirms the spinel cubic structure having space group Fd3m. Further all synthesized samples reveal the single-phase formation without any secondary phase. The lattice parameters and hopping lengths were increases with increase of Dy-Ho concentration. SEM micrographs shows the porous nature for all samples. The crystallite size increases with increase of Dy-Ho concentration. The Dielectric properties of all the samples were explained by using Koop’s phenomenological theory. The real part of dielectric constant, imaginary part of dielectric constant and dielectric loss tangent were decreases with increase of frequency. Th AC conductivity increases with increase of frequency. The real part of impedance spectra decreases with increase of frequency for all samples. The Cole-Cole plots shows the one semicircle for all samples. The high ac conductivity and low dielectric loss observed for all samples at high frequency region and this samples are reasonable for power transformer applications at high frequencies.

scholarly journals Effect of Zinc Doping on the Electrical and Dielectric Properties of CCTO Compound Synthesized by Solid-State Method

2021 ◽  
Vol 33 (9) ◽  
pp. 2000-2006
Author(s):  
M. Slaoui ◽  
N. Gouitaa ◽  
Y. El Issmaeli ◽  
A. Harrach ◽  
F. Abdi ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
X Ray ◽  
Zn Concentration ◽  
Zinc Doping ◽  
Electrical And Dielectric Properties

In this work, the influence of zinc doping on structural and dielectric properties of CaCu(3-x)ZnxTi4O12 (CCZxTO with x = 0, 2.5, 5, 7.5, 10, 12.5 and 15%) ceramics sintered at 1000 ºC for 8 h was studied. The ceramic samples were prepared by the conventional solid-state and calcined at 1050 ºC for 4 h. The X-ray diffraction (XRD) analysis of pure and Zn-doped CCTO were analyzed by using Rietveld refinement with cubic CCTO phase with no trace impurity phase. The scanning electron microscopy (SEM) investigation showed that for Zn-doped CCTO, the grains distributions were homogenous with average sizes which decreased with increasing of Zn concentration. The dielectric permittivity as function of temperature showed two dielectric anomalies (weakly and strong) and the dielectric constant value largely decreased for x = 2.5%, which is about tree magnitude smaller than the pure ceramic. Then it increased and reached a maximum at x = 10%, which is larger than the value of pure ceramic. And for x > 10%, the dielectric constant decreased for about two magnitude smaller than the ceramic at x = 10%. The cole-cole diagramm for all the samples showed existence of two semi-arcs attributed to the grains and grains boundaries. It was found that the Rg values were much smaller than the Rgb value. This give an evidance on the formation of interior barrier layer capacity (IBLC).

scholarly journals Preparation and studying Structural and Electrical properties of nano Co3O4

2019 ◽  
Vol 24 (6) ◽  
pp. 126
Author(s):  
Nawar Thamer Mohammed ◽  
Wasfi Mohammed Kadem
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Sol Gel ◽  
Frequency Range ◽  
Nano Powder ◽  
Structural And Electrical Properties ◽  
Electrical And Dielectric Properties ◽  
Lcr Meter

In this study (Cobalt oxide) nano powder prepared using sol-gel method with a crystallite size 22 nm By testing XRD  and by matching with card (JCPDS) files No.( 00-042-1467). Electrical and dielectric properties like (Dielectric constant, resistivity, electrical conductivity) are studied by LCR meter with frequency range from (50 Hz) to (5 MHz ). It was noted that the resistivity and dielectric constant was decreasing while electrical conductivity increased with increased  frequency    http://dx.doi.org/10.25130/tjps.24.2019.118  

Tuning the mechanical and dielectric properties of zinc incorporated hydroxyapatite

2020 ◽  
Vol 16 ◽  
Author(s):  
Alliya Qamar ◽  
Rehana Zia ◽  
Madeeha Riaz
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Bone Growth ◽  
Healing Process ◽  
Secondary Phase ◽  
Chemical Precipitation ◽  
Hexagonal Structure ◽  
Precipitation Method ◽  
Low Frequencies ◽  
A Minor

Background: Hydroxyapatite is similar to bone mineral in chemical composition, has good biocompatibility with host tissue and bone. Objective: This work aims to tailor the mechanical and dielectric properties of hydroxyapatite with zinc sudstitution, to improve wearability of implant and accelerate the healing process. Method: Pure and zinc incorporated hydroxyapatite Ca10(PO4)6(OH)2 samples have been successfully prepared by means of the chemical precipitation method. Results: The results showed that hydroxyapatite(Hap) having hexagonal structure was the major phase identified in all the samples. It was found that secondary phase of β-tricalcium phosphate (β-TCP) formed due to addition of Zinc resulting in biphasic structure BCP (Hap + β-TCP). A minor phase of ZnO also formed for higher concentration of Zn (Zn ≥ 2mol%) doping. It was found that the Zn incorporation to Hap enhanced both mechanical and dielectric properties without altering the bioactive properties. The microhardness increased upto 0.87 GPa for Zn concentration equal to 1.5mol%, which is comparable to the human bone ~0.3 - 0.9 GPa. The dielectric properties evaluated in the study showed that 1.5 mol% Zn doped hydroxyapatite had highest dielectric constant. Higher values of dielectric constant at low frequencies signifies its importance in healing processes and bone growth due to polarization of the material under the influence of electric field. Conclusion: Sample Z1.5 having 1.5 mol% Zn doping showed the most optimized properties suitable for bone regeneration applications.

scholarly journals Effect of Terminal Groups on Thermomechanical and Dielectric Properties of Silica–Epoxy Composite Modified by Hyperbranched Polyester

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2451
Author(s):  
Jianwen Zhang ◽  
Dongwei Wang ◽  
Lujia Wang ◽  
Wanwan Zuo ◽  
Lijun Zhou ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Binding Energy ◽  
Epoxy Resin ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
Mean Square Displacement ◽  
Mean Square ◽  
Hyperbranched Polyester ◽  
Free Volume Fraction

To study the effect of hyperbranched polyester with different kinds of terminal groups on the thermomechanical and dielectric properties of silica–epoxy resin composite, a molecular dynamics simulation method was utilized. Pure epoxy resin and four groups of silica–epoxy resin composites were established, where the silica surface was hydrogenated, grafted with silane coupling agents, and grafted with hyperbranched polyester with terminal carboxyl and terminal hydroxyl, respectively. Then the thermal conductivity, glass transition temperature, elastic modulus, dielectric constant, free volume fraction, mean square displacement, hydrogen bonds, and binding energy of the five models were calculated. The results showed that the hyperbranched polyester significantly improved the thermomechanical and dielectric properties of the silica–epoxy composites compared with other surface treatments, and the terminal groups had an obvious effect on the enhancement effect. Among them, epoxy composite modified by the hyperbranched polyester with terminal carboxy exhibited the best thermomechanical properties and lowest dielectric constant. Our analysis of the microstructure found that the two systems grafted with hyperbranched polyester had a smaller free volume fraction (FFV) and mean square displacement (MSD), and the larger number of hydrogen bonds and greater binding energy, indicating that weaker strength of molecular segments motion and stronger interfacial bonding between silica and epoxy resin matrix were the reasons for the enhancement of the thermomechanical and dielectric properties.

Sign in / Sign up

Export Citation Format

Share Document