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.

Electrical Conductivity Prediction in Langasite for Optimized Microbalance Performance at Elevated Temperatures

2002 ◽  
Vol 756 ◽  
Author(s):  
Huankiat Seh ◽  
Harry Tuller ◽  
Holger Fritze
Keyword(s):  
Electrical Conductivity ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
High Temperatures ◽  
Gas Sensors ◽  
Elevated Temperatures ◽  
Operating Conditions ◽  
Total Conductivity ◽  
Defect Model ◽  
Partial Pressures

ABSTRACTThe performance of the langasite-based crystal microbalance is limited due to reductions in its resistivity at high temperatures and reduced oxygen partial pressures. In this work, we utilize a recently developed defect model to predict the dependence of the ionic and electronic contributions to the total conductivity of langasite on temperature, oxygen partial pressure and acceptor and donor dopants. These results are used to select the type and concentrations of dopants expected to provide extended operating conditions for langasite-based gas sensors and crystal microbalances.

Electrical conductivity of p-type BiOCl nanosheets

2015 ◽  
Vol 51 (13) ◽  
pp. 2629-2632 ◽  
Author(s):  
Yoon Myung ◽  
Fei Wu ◽  
Sriya Banerjee ◽  
Jeunghee Park ◽  
Parag Banerjee
Keyword(s):  
Electrical Conductivity ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Electrical Conduction ◽  
Hydrolysis Method ◽  
P Type

BiOCl nanosheets were synthesized using a facile hydrolysis method and their p-type electrical conduction as a function of oxygen partial pressure was measured.

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.

Electrical Properties of Donor and Acceptor Doped Gd2Ti2O7

1994 ◽  
Vol 369 ◽  
Author(s):  
Igor Kosacki ◽  
Harry L. Tuller
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Conductivity Measurements ◽  
Donor And Acceptor ◽  
Mn Doped

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.

scholarly journals Electrical Properties of Cubic InN And GaN Epitaxial Layers as a Function of Temperature

2000 ◽  
Vol 5 (S1) ◽  
pp. 216-222
Author(s):  
J.R.L. Fernandez ◽  
V.A. Chitta ◽  
E. Abramof ◽  
A. Ferreira da Silva ◽  
J.R. Leite ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electrical Properties ◽  
Carrier Concentration ◽  
Doping Level ◽  
Type Conductivity ◽  
Si Doping ◽  
Donor And Acceptor ◽  
Cubic Gan ◽  
Si Doped ◽  
P Type

Carrier concentration and mobility were measured for intrinsic cubic InN and GaN, and for Si-doped cubic GaN as a function of temperature. Metallic n-type conductivity was found for the InN, while background p-type conductivity was observed for the intrinsic GaN layer. Doping the cubic GaN with Si two regimes were observed. For low Si-doping concentrations, the samples remain p-type. Increasing the Si-doping level, the background acceptors are compensated and the samples became highly degenerated n-type. From the carrier concentration dependence on temperature, the activation energy of the donor and acceptor levels was determined. Attempts were made to determine the scattering mechanisms responsible for the behavior of the mobility as a function of temperature.

Defect chemistry of donor-doped BaTiO3 with BaO-excess for reduction resistant PTCR thermistor applications – redox-behaviour

2020 ◽  
Vol 22 (15) ◽  
pp. 8219-8232
Author(s):  
Christian Pithan ◽  
Hayato Katsu ◽  
Rainer Waser
Keyword(s):  
Electrical Conductivity ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Defect Chemistry ◽  
Redox Behaviour ◽  
Ptcr Effect

The electrical conductivity of donor-doped BaTiO3 thermistor ceramics with excessive BaO revealing a reduction-persistent PTCR effect has been carefully examined depending on materials’ composition and oxygen partial pressure at moderate temperatures between 973 and 1273 K.

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.

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