Electrical properties of the country rocks of the Karaganda coalfield electrical conductivity and dielectric relaxation

1976 ◽  
Vol 12 (4) ◽  
pp. 432-435 ◽  
Author(s):  
M. P. Tonkonogov ◽  
V. A. Veksler ◽  
M. M. Dzhangozin ◽  
T. A. Vorob'eva
Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 697 ◽  
Author(s):  
Darya Meisak ◽  
Jan Macutkevic ◽  
Artyom Plyushch ◽  
Polina Kuzhir ◽  
Algirdas Selskis ◽  
...  

The electrical properties of epoxy/MWCNT (multi-walled carbon nanotubes)/MnFe2O4 hybrid composites loaded with MWCNTs (below, 0.09 vol.%, and above, 0.58 vol.%, percolation threshold) and varying concentrations of MnFe2O4 up to 10 vol.% were studied in a wide frequency range (20 Hz–40 GHz) at different temperatures (20 K–500 K). At low frequencies, the dielectric permittivity and the electrical conductivity of composites with fixed amounts of MWCNT are strongly dependent on MnFe2O4 content. For MWCNT concentrations above the percolation threshold (i.e., 0.58 vol.%), the electrical conductivity highly decreases with the increase of the MnFe2O4 fraction. In contrast, for the epoxy/MWCNT just below the onset of electrical conductivity (0.09 vol.% of MWCNTs), there exists an optimal concentration of MnFe2O4 inclusions (i.e., 0.025 vol.%), leading to a dramatic increase of the electrical conductivity by three orders of magnitude. The electrical transport in composites is mainly governed by electron tunneling at lower temperatures (below 200 K), and it is highly impacted by the matrix conductivity at higher temperatures (above 400 K). The electrical properties were discussed in terms of the Maxwell–Wagner relaxation and distributions of relaxation times. A non-invasive platform based on dielectric relaxation spectroscopy was proposed for enhancing the synergetic effect coursed by using multiple nanoinclusions in polymer composites just below the percolation threshold.


2018 ◽  
Vol 1 (1) ◽  
pp. 26-31 ◽  
Author(s):  
B Babu ◽  
K Mohanraj ◽  
S Chandrasekar ◽  
N Senthil Kumar ◽  
B Mohanbabu

CdHgTe thin films were grown onto glass substrate via the Chemical bath deposition technique. XRD results indicate that a CdHgTe formed with a cubic polycrystalline structure. The crystallinity of CdHgTe thin films is gradually deteriorate with increasing the gamma irradiation. EDS spectrums confirms the presence of Cd, Hg and Te elements. DC electrical conductivity results depicted the conductivity of CdHgTe increase with increasing a gamma ray dosage


1990 ◽  
Vol 55 (12) ◽  
pp. 2933-2939 ◽  
Author(s):  
Hans-Hartmut Schwarz ◽  
Vlastimil Kůdela ◽  
Klaus Richau

Ultrafiltration cellulose acetate membrane can be transformed by annealing into reverse osmosis membranes (RO type). Annealing brings about changes in structural properties of the membranes, accompanied by changes in their permeability behaviour and electrical properties. Correlations between structure parameters and electrochemical properties are shown for the temperature range 20-90 °C. Relations have been derived which explain the role played by the dc electrical conductivity in the characterization of rejection ability of the membranes in the reverse osmosis, i.e. rRO = (1 + exp (A-B))-1, where exp A and exp B are statistically significant correlation functions of electrical conductivity and salt permeation, or of electrical conductivity and water flux through the membrane, respectively.


RSC Advances ◽  
2015 ◽  
Vol 5 (94) ◽  
pp. 76783-76787 ◽  
Author(s):  
H. L. Wang ◽  
X. K. Ning ◽  
Z. J. Wang

Au–LaNiO3 (Au–LNO) nanocomposite films with 3.84 at% Au were firstly fabricated by one-step chemical solution deposition (CSD), and their electrical properties were investigated.


2006 ◽  
Vol 111 ◽  
pp. 99-102 ◽  
Author(s):  
A.A. Ahmed ◽  
Faiz Mohammad

The films of polyaniline:polyethyleneterephthalate films were prepared by polymerizing aniline soaked in polyethyleneterephthalate films of different thicknesses. The films were characterized by FTIR as well as for their electrical properties. The electrical properties of the films were observed to be of good quality as almost all the films showed a great increase in their electrical conductivity from insulator to semiconductor region after doping with hydrochloric acid. All the films in their doped state follow the Arrhenius equation for the temperature dependence of electrical conductivity from 35 to 115oC. The thermooxidative stability was studied by thermogravimetry and differential thermal analysis. The stability in terms of dc electrical conductivity retention was also studied under ambient conditions by two slightly different techniques viz. isothermal and cyclic techniques. The dc electrical conductivity of the films was found to be stable below 90oC for all the films under ambient conditions.


2010 ◽  
Vol 160-162 ◽  
pp. 1331-1335 ◽  
Author(s):  
Chuan Bo Li ◽  
Kristel Fobelets ◽  
S.N. Syed Jalal ◽  
Wei A. Ng ◽  
Zahid A.K. Durrani

The influence of the chemical modification on the electrical property of Si nanowire array was studied. It is found that H-terminated Si nanowire has a better electrical conductivity while OH-passivation could increase their resistance. It is believed that the introducing of OH group on the surface nanowire increases the interface traps and it is confirmed by our 1/f noise measurement.


2002 ◽  
Vol 750 ◽  
Author(s):  
Yoshifumi Aoi ◽  
Kojiro Ono ◽  
Kunio Sakurada ◽  
Eiji Kamijo

ABSTRACTAmorphous CNx thin films were deposited by pulsed laser deposition (PLD) combined with a nitrogen rf radical beam source which supplies active nitrogen species to the growing film surface. The deposited films were characterized by X-ray photoelectron spectroscopy (XPS), Raman scattering, and Fourier transform infrared (FTIR) spectroscopy. Nitrogen content of the deposited films increased with increasing rf input power and N2 pressure in the PLD chamber. The maximum N/C ratio 0.23 was obtained at 400 W of rf input power and 1.3 Pa. XPS N 1s spectra shows the existence of several bonding structures in the deposited films. Electrical properties of the deposited films were investigated. The electrical conductivity decreased with increasing N/C atomic ratio. Temperature dependence of electrical conductivity measurements indicated that electronic conduction occurred by variable-range hopping between p electron localized states.


1994 ◽  
Vol 369 ◽  
Author(s):  
Igor Kosacki ◽  
Harry L. Tuller

The results of electrical conductivity measurements on Nb, W, and Mn-doped Gd2Ti2O7 are presented. A correlation between electrical conductivity, the oxygen partial pressure and type of dopants has been obtained. The source of the different PO2 dependence for Mn-doped material is discussed.


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