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

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  

2019 ◽  
Vol 8 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Dalal Hassan ◽  
Ahmed Hashim Ah-yasari

The preparation of (polystyrene-copper oxide) nanocomposites have been investigated for piezoelectric application. The copper oxide nanoparticles were added to polystyrene by different concentrations are (0, 4, 8 and 12) wt.%. The structural and A.C electrical properties of (PS-CuO) nanocomposites were studied. The results showed that the dielectric constant and dielectric loss of (PS-CuO) nanocomposites decrease with increase in frequency. The A.C electrical conductivity increases with increase in frequency. The dielectric constant, dielectric loss and A.C electrical conductivity of polystyrene increase with increase in copper oxide nanoparticles concentrations. The results of piezoelectric application showed that the electrical resistance of (PS-CuO) nanocomposites decreases with increase in pressure.


2021 ◽  
Vol 19 (4) ◽  
pp. 38-46
Author(s):  
Manar S. Toman ◽  
Sameer Hassan Al-nesrawy

This paper presents the work conducted on preparing (PbO PVA-PEG) nanocomposites through adding the different weight concentrations of lead oxide (0,1,3,5,7 wt%). The structural aspects such as optical microscope, FTIR and electrical features of nanocomposites (PVA-CMC/PbO) were examined. The resulting data shows that the dielectric constant decreased along with the decline of dielectric loss, whereas the frequency value rose while applying of an electric field. As for the electrical conductivity AC, the dielectric loss and dielectric constant of all samples rose along with the increase in lead oxide concentration.


2009 ◽  
Vol 23 (31n32) ◽  
pp. 3785-3791
Author(s):  
SUNG-PILL NAM ◽  
HYUN-JI NOH ◽  
SUNG-GAP LEE ◽  
SEON-GI BAE ◽  
YOUNG-HIE LEE

The heterolayered BT/BNT thick films were fabricated by screen printing techniques on alumina substrates electrodes with Pt . Their structure and ferroelectric properties were investigated with the heterolayered tetragonal/rhombohedral structure composed of the BT and the BNT thick films. The structural and electrical properties of the heterolayered BT/BNT thick films were studied. The dielectric properties such as dielectric constant, loss and remanent polarization of the heterolayered BT/BNT thick films were superior to those of single composition BNT, and those values for the heterolayered BT/BNT thick films were 1455, 0.025 and 12.63 µC/cm2.


2021 ◽  
Vol 39 (3) ◽  
pp. 305-318
Author(s):  
Wipawadee Toumvong ◽  
Pornnita Chitcharoentaweechoke ◽  
Nuchnapa Tangboriboon

Abstract Eggshell is a rich source of calcium that is a dielectric material used for doping in a superconductor. Yttrium calcium barium copper oxide (Y x Ca1−x Ba2Cu3O7) was prepared using the sol-gel process and fired at 900 °C or 1,000 °C. The stoichiometric ratio of the raw materials Y2O3:BaCl2:CuO:CaO was 1:2:3:1 based on the molar mass. The obtained YCaBCO had an orthorhombic crystal structure composed of distorted oxygen-deficient perovskite. The orthorhombic structure was unsymmetrical, providing a substantial increase in the physical electromagnetic properties of the superconductor. The YBCO-900-reference analyzed using an impedance analyzer in the range from 500 Hz to (1 × 106) Hz and at room temperature (27 °C) had the following values for capacitance, electrical conductivity, and dielectric constant ± standard error: 8,286.70 ± 28.49 pF, (3.60 ± 0.01) × 107 S/m, and 1,874.794 ± 6.446, respectively. The YCaBCO-900-eggshell (Y x Ca1−x Ba2Cu3O7) analyzed at 500 Hz at room temperature (27 °C) had high values for capacitance, electrical conductivity, and dielectric constant, namely, 8,540.10 ± 2.00 pF, (1.32 ± 0.00) × 108 S/m, and 1,988.540 ± 0.500, respectively. Furthermore, the YCaBCO-900-eggshell had electrical properties (capacitance, conductivity, and dielectric constant values) higher than those of YCaBCO-900-commercial grade measured under the same conditions. The YCaBCO-900-com grade had capacitance of 8,225.75 ± 0.73 pF, electrical conductivity of (1.40 ± 0.01) × 108 S/m, and dielectric constant of 1,874.59 ± 0.17, respectively. Therefore, eggshell is an alternative dielectric material useful for doping in yttrium barium copper oxide (YBCO) to form YCaBCO, thus causing an increase in its electrical properties. The obtained superconductor is a candidate that could be applied in many industries.


2020 ◽  
Vol 1 (1) ◽  
pp. 13-25
Author(s):  
Salama A. H.

Electrical properties of some new cyclopentenone derivatives have been studied. The structures of prepared samples were characterized by (UV), (XRD) and (SEM). The dependence of electrical properties such as σdc , σac , ɛ' and ɛ'' on frequency and temperature were studied at frequency range from 50 Hz to 5 MHz and the temperature range from 25oC to 140oC. It was found that, ɛ' decreased with increasing frequency while it increases with increasing temperatures within the used ranges. Moreover, dielectric constant is structural dependent which is obvious from the variation of dielectric constant for each sample. Ac-electrical conductivity increased with increasing frequency which was attributed to the polarization of the charge carriers. The temperature dependence of dc-electrical conductivity show typical Arrhenius relation for the three prepared samples. The activation energy calculated from Arrhenius equation and the results are discussed in detailed.


2016 ◽  
Vol 2 (1) ◽  
pp. 13-18
Author(s):  
Imran Khan ◽  
M S A Khan

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Aref Naimzad ◽  
Yousef Hojjat ◽  
Mojtaba Ghodsi

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.


2020 ◽  
Vol 66 (5 Sept-Oct) ◽  
pp. 573
Author(s):  
K. Bashir Bashir ◽  
M. -ul-Islam ◽  
M. Ajmal ◽  
M. Waqas Nafees ◽  
A. Iftikhar ◽  
...  

Chromium substituted copper base spinel ferrites (Ni0.3Cu0.7)CrxFe2-xO4 were prepared by Sol-gel method. Structural, magnetic and electrical properties were studied by utilizing X-ray diffractometer, Vibrating sample magnetometer, and precision LCR-meter using lab-tracer software. The X-ray diffraction analysis confirmed the formation of single phase fcc structure of the samples. The lattice constant and crystallite size decreased from 8.37-8.23Å and 53.09-35.36nm respectively with increasing content of Cr3+ ions. From MH loops it was observed that the saturation magnetization decreased and coercivity increased with increasing content of Cr3+ ions. Dc resistivity increased with increase of Cr3+ concentration and decreased with increase in temperature which shows the semiconducting behavior of ferrites. The dielectric constant, dielectric loss and tangent loss decreased with increase of Cr3+ concentration. The dielectric constant follows bilayer Maxwell Wagner model and Koop’s phenomenological theory while ac conductivity increased with increasing frequency following Jonscher’s power law.


2020 ◽  
Author(s):  
seyed ebrahim Mousavi Ghahfarokhi ◽  
Foruzan Bazdar ◽  
Iraj Kazeminezhad ◽  
Elham Mohammadzadeh Shobegar

Abstract PbFe12-xNixO19 nanoparticles (x = 0-1) were prepared by a sol–gel method. The influence of Ni2+ substitution on structural, magnetic and dielectric properties of PbFe12O19 nanoparticles was investigated. The samples of PbFe12-xNixO19 nanoparticles have been characterized by the X-ray diffractomere (XRD), Fourier transform infrared spectrometer (FT-IR), scanning electron spectrometer (SEM), vibrating sample magnetometer (VSM), and an LCR meter. The results reveal that PbFe12-xNixO19 compounds up to x = 0.2 are single phase. The bands of absorption in the 400– 500 cm-1 and the bands of absorption in the range of 500 -600 cm-1, corresponding to the formation of octahedral and tetrahedral sites which confirms the presence of metal– oxygen stretching band in ferrites. Also, SEM images show that by increasing Ni2+ doping grains size have been increased. However, for x > 0.2, the secondary Ni spinel ferrite (NiFe2O4) appears which the saturation magnetization and magnetic coercivity decreases. In addition, Ni2+substitution reduces the dielectric constant, dielectric loss, and ac electrical conductivity for all samples decrease rapidly with increasing applied field frequency and reaches a constant value beyond a certain frequency which this is characteristic of the normal dielectric behaviour of ferrites and has been investigated by Maxwell–Wagner’s two-layer model and Koop’s theory. The variation in ac conductivity (σac) with frequency shows that the electrical conductivity in these ferrites is mainly attributed to the electron hopping mechanism.Therefore; all single-phase Ni2+ substituted samples are suitable for use in magnetic recording media and microwave devices.


2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
M. S. Aziz ◽  
A. G. Mostafa ◽  
A. M. Youssef ◽  
S. M. S. Youssif

The AC conductivity and dielectric parameters of the glassy system of (70-x) V2O5· x(Zn/Pb)· 10SrO · 20FeO (x = 0, 5, 10, and 15) glasses have been investigated. The frequency and temperature dependence of dielectric constant (ε′) and dielectric loss (ε′′) is studied in the frequency range 100 Hz–5 MHz and in the temperature range 300–460 K. Dielectric dispersion is observed in all samples as Zn/Pb increase content in the (70-x)V2O5· x(Zn/Pb)·10SrO·20FeO systems. These results are explained on the basis of a Debye-type relaxation. It is also observed that the activation energy increases on increasing the Zn/Pb contents in this system.


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