Modelling of Electrical Conductivity of n-p Ceramic Composite Using Equivalent Circuits

1995 ◽  
Vol 411 ◽  
Author(s):  
Gyeong Man Choi ◽  
Seok Taek Jun
Keyword(s):  
Electrical Conductivity ◽  
Grain Size ◽  
Ceramic Composite ◽  
Composition Dependence ◽  
Equivalent Circuits ◽  
Total Conductivity ◽  
Fractional Change ◽  
Total Electrical Conductivity ◽  
Type Semiconductor ◽  
P Type

ABSTRACTComposition dependence of electrical conductivity of ceramic composite was analyzed using a ZnO(n-type semiconductor)-CuO(p-type semiconductor) composite as a model. The contributions from grain and grain boundaries to the total conductivity of the composite were determined. New equivalent circuits were proposed which represented the distribution and connection of n and p grains and the total electrical conductivity was analyzed using the proposed circuits. Dominant equivalent circuit changed with composition and the total conductivity was determined by the exponential fractional change of two equivalent circuits. Effect of grain size on the grain boundary and total conductivity were also examined.

Composition Dependence of The Electrical Conductivity of n-p Ceramic Composite

1994 ◽  
Vol 357 ◽  
Author(s):  
Seok-Taek Jun ◽  
Gyeong-Man Choi
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Grain Boundaries ◽  
Ceramic Composite ◽  
Composition Dependence ◽  
Volume Fraction ◽  
Ceramic Composites ◽  
Equivalent Circuits ◽  
Total Resistance ◽  
Impedance Response

AbstractElectrical properties of ZnO-CuO ceramic composites with varying composition were investigated. The electrical conductivity increased with increasing CuO volume fraction between 1 mol% to 95 mol%. Impedance response showed three semicircles, indicating three resistive elements contributing to the total resistance of the composite. A new model based on the equivalent circuits was developed to explain the contribution of grain boundaries to the resistance of the composite. The change of electrical conductivity was explained by the probability change of two equivalent circuits.

Transparent P-type Conducting LaCuOS Layered Oxysulfide

2001 ◽  
Vol 666 ◽  
Author(s):  
Kazushige Ueda ◽  
Shin-ichiro Inoue ◽  
Sakyo Hirose ◽  
Hiroshi Kawazoe ◽  
Hideo Hosono
Keyword(s):  
Electrical Conductivity ◽  
Visible Region ◽  
Optoelectronic Devices ◽  
Promising Material ◽  
High Transparency ◽  
Conducting Oxides ◽  
Excitonic Absorption ◽  
Type Semiconductor ◽  
Optical Applications ◽  
P Type

ABSTRACTMaterials design for transparent p-type conducting oxides was extended to oxysulfide system. LaCuOS was selected as a candidate for a transparent p-type semiconductor. It was found that the electrical conductivity of LaCuOS was p-type and controllable from semiconducting to semi-metallic states by substituting Sr2+ for La3+. LaCuOS films showed high transparency in the visible region, and the bandgap estimated was approximately 3.1 eV. Moreover, it was revealed that LaCuOS showed sharp excitonic absorption and emission at the bandgap edge, which is advantageous for optical applications. A layered oxysulfide, LaCuOS, was proposed to be a promising material for optoelectronic devices.

Ceramic composite membranes based on Bi3Ru3O11 – Bi1,6Er0,4O3 for obtaining of oxygen

2021 ◽  
Vol 6 ◽  
pp. 22-28
Author(s):  
P. E. Dergacheva ◽  
◽  
I. V. Kulbakin ◽  
S. V. Fedorov ◽  
A. S. Lysenkov ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ceramic Composite ◽  
Oxygen Permeability ◽  
Total Porosity ◽  
Composite Membranes ◽  
Ceramic Composites ◽  
Argon Atmosphere ◽  
Pure Oxygen ◽  
Total Conductivity ◽  
Temperature Dependence Of Conductivity

Using hot uniaxial pressing in an argon atmosphere with a stress of 35 MPa and with a holding at 800 °C for 1 hour, ceramic composites of Bi3Ru3O11 – 50, 65 wt % Bi1,6Er0,4O3 were obtained. It was found that phase composition of the composites does not change during gas chromatographic testing at 800 °C and well corresponds to the specified one. Microstructure of the obtained composites was tested and the formation of dense composites with a total porosity of less than 1% and with a uniform distribution of the Bi3Ru3O11 and Bi1,6Er0,4O3 components in bulk of material was demonstrated. Transport properties (total conductivity, oxygen fluxes and selectivity of separating oxygen over nitrogen) of the obtained composites at 600 – 800 °C had been investigated. Thus, at 800 °C the electrical conductivity of Bi3Ru3O11 – 50, 65 wt % Bi1,6Er0,4O3 was about 200 and 50 Ohm–1∙cm–1, respectively, while the metallic nature of their temperature dependence of conductivity is correlated to that for the Bi3Ru3O11. The value of oxygen permeability for the obtained ceramic composites of about 7∙10–9 mol·cm–1·s–1 at 800 °C, which is compared to other membrane materials based on bismuth oxide, demonstrated the potential of their further use in the tasks for obtaining of pure oxygen from air.

scholarly journals Thermoelectric Behavior of BaZr0.9Y0.1O3−d Proton Conducting Electrolyte

Membranes ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 120 ◽  
Author(s):  
Tsvetkov ◽  
Ivanov ◽  
Malyshkin ◽  
Sereda ◽  
Zuev
Keyword(s):  
Activation Energy ◽  
Seebeck Coefficient ◽  
Small Polaron ◽  
Transference Numbers ◽  
Total Conductivity ◽  
Clear Understanding ◽  
Proton Conducting ◽  
Total Electrical Conductivity ◽  
P Type ◽  
Electronic Defects

BaZr0.9Y0.1O3-δ (BZY10), a promising proton conducting material, exhibits p-type conduction under oxidative conditions. Holes in BZY10 are of the small polaron type. However, there is no clear understanding at which places in the lattice they are localized. The main objectives of this work were, therefore, to discuss the nature of electronic defects in BZY10 on the basis of the combined measurements of the thermo-EMF and conductivity. Total electrical conductivity and Seebeck coefficient of BZY10 were simultaneously studied depending on partial pressures of oxygen (pO2), water (pH2O) and temperature (T). The model equation for total conductivity and Seebeck coefficient derived on the basis of the proposed defect chemical approach was successfully fitted to the experimental data. Transference numbers of all the charge carriers in BZY10 were calculated. The heat of transport of oxide ions was found to be about one half the activation energy of their mobility, while that of protons was almost equal to the activation energy of their mobility. The results of the Seebeck coefficient modeling indicate that cation impurities, rather than oxygen sites, should be considered as a place of hole localization.

Synergistic effect by Na doping and S substitution for high thermoelectric performance of p-type MnTe

2017 ◽  
Vol 5 (21) ◽  
pp. 5076-5082 ◽  
Author(s):  
Yangyang Ren ◽  
Junyou Yang ◽  
Qinghui Jiang ◽  
Dan Zhang ◽  
Zhiwei Zhou ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Synergistic Effect ◽  
Band Gap ◽  
Room Temperature ◽  
Hole Concentration ◽  
Direct Band Gap ◽  
Na Doping ◽  
Type Semiconductor ◽  
Direct Band ◽  
P Type

Pristine MnTe is a p-type semiconductor with a relatively low hole concentration of 1018 cm−3, low electrical conductivity, and thus poor TE performance at room temperature owing to the broad direct band gap of 1.27 eV.

New Mixed Conductors Based on Doped Layered Perovskites

1998 ◽  
Vol 548 ◽  
Author(s):  
Carlos Navas ◽  
Harry L. Tuller ◽  
Hans-Conrad zur Loye
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Electronic Conductivity ◽  
Total Conductivity ◽  
Mixed Conductors ◽  
Type Conductivity ◽  
P Type ◽  
Layered Perovskites

ABSTRACTA series of doped Ruddlesden-Popper phases, of general formula Sr3Ti2−xMxO7−δ (M=Al, Ga, Co), were synthesized and their electrical conductivity characterized as a function of temperature and oxygen partial pressure. For fixed-valent dopants, p-type conductivity predominates at p(O2)>10−5 atm, followed by a p(O2)-independent electrolytic regime, and n-type electronic conductivity at very low p(O2). The electrolytic regime exhibits activation energies in the range 1.7-1.8 eV. Doping with transition metals such as Co results in a very significant increase in total conductivity with a p-type conductivity at high p(O2). Furthermore, an apparent ionic regime at intermediate p(O2) is observed, characterized by high conductivity (>10−2 S/cm at 700 °C) and low activation energy (0.7 eV). This interpretation is consistent with iodometric measurements as interpreted by a defect chemical model. Other measurements are in progress to confirm this conclusion.

scholarly journals Effect of Annealing Temperature of Cugao2 thin Films by Using RF Magnetron Sputtering Technique on Optical and Structural Properties

2018 ◽  
Vol 7 (4.30) ◽  
pp. 213
Author(s):  
Lam Wai Yip ◽  
Afishah Alias ◽  
Asmahani Binti Awang ◽  
Abu Bakar Bin Abd Rahman ◽  
Khairul Anuar Bin Mohamad ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Magnetron Sputtering ◽  
Quartz Substrate ◽  
Rf Magnetron Sputtering ◽  
Optical Transparency ◽  
Oxide Material ◽  
Optimum Result ◽  
Type Semiconductor ◽  
P Type

Cu-based conductive oxide such as CuGaO2 is seen to be a promising transparent p-type oxide material. The study of p-type semiconductor CuGaO2 thin films have been carried out to investigate the effects of different parameters in providing the optimum result in achieving good optical transparency and conductivity of the thin film. The CuGaO2 thin films were fabricated on quartz substrate via the Radio Frequency (RF) magnetron sputtering technique with varying substrate temperatures and different annealing temperatures. The p-type thin films were deposited at a temperature ranging from room temperature, 100°C, 200°C and 300°C. The samples were also annealed varying from temperature of 500°C, 600°C, 700°C and 800°C. The fabricated sample were characterized using X-ray diffraction (XRD), UV-Visible spectroscopy, and atomic force microscope (afm). XRD showed a peak at 2θ = 36.10° (012). The optical transparency values achieved from UV-Vis spectrometer were seen to be approximately 80% and the bandgaps were found to be in the range of 3.34-3.43 eV which is in line with the bandgap value from the research on CuGaO2 thin films.  From the afm, the mean surface roughness increases with increasing temperature and this is due to the increment of grain size. The highest grain size was observed at substrate temperature of 200°C.

Effect of Cu doping on the electrical Properties of ZnTe by Vacuum Thermal Evaporation

2018 ◽  
Vol 31 (3) ◽  
pp. 20
Author(s):  
Sarmad M. M. Ali ◽  
Alia A.A. Shehab ◽  
Samir A. Maki
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Hall Effect ◽  
Carrier Concentration ◽  
Hall Mobility ◽  
Cu Doping ◽  
Before And After ◽  
Hall Effect Measurements ◽  
Evaporation Technique ◽  
P Type

In this study, the ZnTe thin films were deposited on a glass substrate at a thickness of 400nm using vacuum evaporation technique (2×10-5mbar) at RT. Electrical conductivity and Hall effect measurements have been investigated as a function of variation of the doping ratios (3,5,7%) of the Cu element on the thin ZnTe films. The temperature range of (25-200°C) is to record the electrical conductivity values. The results of the films have two types of transport mechanisms of free carriers with two values of activation energy (Ea1, Ea2), expect 3% Cu. The activation energy (Ea1) increased from 29meV to 157meV before and after doping (Cu at 5%) respectively. The results of Hall effect measurements of ZnTe , ZnTe:Cu films show that all films were (p-type), the carrier concentration (1.1×1020 m-3) , Hall mobility (0.464m2/V.s) for pure ZnTe film, increases the carrier concentration (6.3×1021m-3) Hall mobility (2m2/V.s) for doping (Cu at 3%) film, but  decreases by increasing Cu concentration.

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