Partial Carbonization of Aromatic Polyimide Films

1999 ◽  
Vol 593 ◽  
Author(s):  
M. Doyama ◽  
A. Ichida ◽  
Y. Inoue ◽  
Y. Kogure ◽  
T. Nozaki ◽  
...  
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Hall Coefficient ◽  
Carrier Density ◽  
Carrier Mobility ◽  
Absolute Temperature ◽  
Polyimide Films ◽  
Aromatic Polyimide ◽  
The Absolute

ABSTRACTAromatic polyimide films are partially carbonized between 700°C and 1000°C. Electrical conductivity and Hall coeficient have been measured. Electrical conductivity is higher at higher measuring temperatures. The electrical conductivity σ can be expressed as σ= σ0exp (–E /kT), where k is the Boltzman constant. T is the absolute temperature. E depends upon the carborized temperature. The experimental data show the Hall coefficient RH is negative, and this implies the carriers are negatively charged, i.e. electrons. The specimens are n-type semiconductors. The carrier density η can be expressed by η= A1 exp (–E1/κT) and carrier mobility μ can be expressed by μ = A1exp ( E2/κT). E, E1andE2 depend upon the carbonized temperature

THE ELECTRICAL CONDUCTIVITY OF MOLTEN OXIDES

1953 ◽  
Vol 31 (11) ◽  
pp. 1009-1019 ◽  
Author(s):  
A. E. Van Arkel ◽  
E. A. Flood ◽  
Norman F. H. Bright
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Absolute Temperature ◽  
Molten State ◽  
Melting Points ◽  
Electrical Conductivities ◽  
The Absolute ◽  
Pattern Of Variation ◽  
Molten Oxides

Electrical conductivities of some molten oxides have been determined. In order of decreasing equivalent conductances at their melting points the oxides investigated were: Li2O, PbO, TeO2, MoO3, Bi2O3, V2O5, Sb2O3, and CrO3. The variation of the observed values of the specific conductivities, K, with the absolute temperature, T, can be described by an equation of the form,[Formula: see text]where A, B, C, etc. are constants. While the experimental data are adequately described by an equation of this form containing only the constants A and B, a slightly better fit is obtained using three constants. The conductivities of the molten oxides follow a pattern of variation from element to element which is substantially the same as that of the molten halides. For elements giving more than one oxide stable in the molten state, the oxide corresponding to the highest state of valency has the lowest conductivity.

scholarly journals Universal mobility characteristics of graphene originating from charge scattering by ionised impurities

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jonathan H. Gosling ◽  
Oleg Makarovsky ◽  
Feiran Wang ◽  
Nathan D. Cottam ◽  
Mark T. Greenaway ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carrier Density ◽  
Carrier Mobility ◽  
Carrier Transport ◽  
Analytical Models ◽  
Pristine Graphene ◽  
High Electron ◽  
Boltzmann Transport ◽  
Transport Parameters ◽  
Wide Range

AbstractPristine graphene and graphene-based heterostructures can exhibit exceptionally high electron mobility if their surface contains few electron-scattering impurities. Mobility directly influences electrical conductivity and its dependence on the carrier density. But linking these key transport parameters remains a challenging task for both theorists and experimentalists. Here, we report numerical and analytical models of carrier transport in graphene, which reveal a universal connection between graphene’s carrier mobility and the variation of its electrical conductivity with carrier density. Our model of graphene conductivity is based on a convolution of carrier density and its uncertainty, which is verified by numerical solution of the Boltzmann transport equation including the effects of charged impurity scattering and optical phonons on the carrier mobility. This model reproduces, explains, and unifies experimental mobility and conductivity data from a wide range of samples and provides a way to predict a priori all key transport parameters of graphene devices. Our results open a route for controlling the transport properties of graphene by doping and for engineering the properties of 2D materials and heterostructures.

The Hall Carrier Mobility of AgBiTe2-Ag2Te Composite

2001 ◽  
Vol 691 ◽  
Author(s):  
T. Sakakibara ◽  
Y. Takigawa ◽  
K. Kurosawa
Keyword(s):  
Electrical Conductivity ◽  
Composite Material ◽  
Composite Materials ◽  
Hall Coefficient ◽  
Carrier Mobility ◽  
Matrix Phase ◽  
Second Phase ◽  
Temperature Range ◽  
The Matrix ◽  
Van Der Pauw

ABSTRACTWe prepared a series of (AgBiTe2)1−x(Ag2Te)x(0≤×≤1) composite materials by melt and cool down [1]. The Hall coefficient and the electrical conductivity were measured by the standard van der Pauw technique over the temperature range from 93K to 283K from which the Hall carrier mobility was calculated. Ag2Te had the highest mobility while the mobility of AgBiTe2was the lowest of all samples at 283K. However the mobility of the (AgBiTe2)0.125(Ag2Te)0.875composite material was higher than the motility of Ag2Te below 243K. It seems that a small second phase dispersed in the matrix phase is effective against the increased mobility.

Thermal and electrical conductivity and magnetoresistance of graphite films prepared from aromatic polyimide films

Carbon ◽  
2012 ◽  
Vol 50 (13) ◽  
pp. 4984-4985 ◽  
Author(s):  
Yutaka Kaburagi ◽  
Takeshi Kimura ◽  
Akira Yoshida ◽  
Yoshihiro Hishiyama
Keyword(s):  
Electrical Conductivity ◽  
Polyimide Films ◽  
Aromatic Polyimide

Research on Hall Effect of Graphene by Var Der Pauw Method

2015 ◽  
Vol 1120-1121 ◽  
pp. 383-387
Author(s):  
Yu Xiang Hui ◽  
Nan An ◽  
Kai Chen ◽  
Xiao Jun Li ◽  
Wei Long Li ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Hall Effect ◽  
Hall Coefficient ◽  
Ohmic Contact ◽  
Carrier Mobility ◽  
Room Temperature ◽  
Two Dimensional ◽  
Measurement Results ◽  
Hall Element

Graphene is a two-dimensional material consisting of single atomic layers of graphite. Its quality is markedly different from conventional graphite and semiconductor material. In this paper, electrical conductivity and Hall Effect of the graphene were measured at room temperature by Var der Pauw method. An ohmic contact of the sample and the electrodes was constructed and tested before the measurement of Hall Effect. With the help of the Var der Pauw method, the Hall voltages of the samples were measured under the static magnetic field and different input currents. Sequentially, a series of Hall parameters of graphene were obtained. The results shown that the Hall coefficient RH is 7.00*10-7 m3/C; the carrier concentration n is 10.52*1024 m-3 that is fifteen orders of magnitude bigger than silicon; the Hall element production sensitivity KH is 6.87*102 m2/C and the carrier mobility was 1,882.54 cm2·V-1·s-1 which is much bigger than silicon. The measurement results in this paper can provide some reference for graphene’s research and application in related areas.

scholarly journals Thermal and electrical conductivity and magnetoresistance of graphite films prepared from aromatic polyimide films

TANSO ◽  
2012 ◽  
Vol 2012 (253) ◽  
pp. 106-115 ◽  
Author(s):  
Yutaka Kaburagi ◽  
Takeshi Kimura ◽  
Akira Yoshida ◽  
Yoshihiro Hishiyama
Keyword(s):  
Electrical Conductivity ◽  
Polyimide Films ◽  
Aromatic Polyimide

Vapour pressure and ideality of the equimolar mixture of H2O and D2O

1980 ◽  
Vol 33 (11) ◽  
pp. 2357 ◽  
Author(s):  
G Jancso ◽  
G Jakli
Keyword(s):  
Experimental Data ◽  
Isotope Effect ◽  
Vapour Pressure ◽  
Liquid Mixture ◽  
Geometric Mean ◽  
Absolute Temperature ◽  
Equimolar Mixture ◽  
The Absolute ◽  
The Law ◽  
The Ideal

The pressure differences between H2O and the equimolar H2O-D2O mixture were measured between 5 and 90°C and the experimental data can be represented by the equation ����������������� In(pH2O/pmix) = 0.076624-88.161/T+25972/T2 where T is the absolute temperature. For comparison the vapour-pressure differences between pure H2O and D2O were also determined. The results show that the H2O-HDO-D2O liquid mixture does not deviate from the ideal behaviour within the limits of the experimental data. The present investigation supports the earlier conclusion that the law of the geometric mean for the vapour-pressure isotope effect in the series H2O, HDO and D2O is not obeyed.

Electrical transport and band structure of GaAs

1979 ◽  
Vol 57 (2) ◽  
pp. 233-242 ◽  
Author(s):  
H. J. Lee ◽  
J. Basinski ◽  
L. Y. Juravel ◽  
J. C. Woolley
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Band Structure ◽  
Hall Coefficient ◽  
Electrical Transport ◽  
Theoretical Calculations ◽  
Deformation Potential ◽  
Coupling Coefficients ◽  
Band Energy ◽  
Temperature Coefficients

Measurements of electrical conductivity σ and Hall coefficient RH have been made as a function of temperature in the range room to 500 °C on single crystal n-type tellurium doped samples of GaAs with carrier concentrations in the range 7.9 × 1021 to 4.7 × 1024/m3. Theoretical calculations of σ and RH have been made on a three band (Γ, L, X) model using the method of Fletcher and Butcher and the resulting values fitted to the experimental data by using the temperature coefficients of the band energy differences and various deformation potentials and band coupling coefficients as adjustable parameters. The results confirm the band ordering proposed by Aspnes but give slightly different temperature coefficient values. Values are given for the deformation potentials and band coupling coefficients and in particular the deformation potential of the Γ band is found to be 16.0 ± 0.5 eV.

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