Effect of Morphology on the Electrical Transport Properties of Polyaniline Films for Electronic Applications

1997 ◽  
Vol 488 ◽  
Author(s):  
S. S. Hardaker ◽  
K. Eaiprasertsak ◽  
J. Yon ◽  
R. V. Gregory ◽  
G. X. Tessema
Keyword(s):  
Temperature Dependence ◽  
Electrical Transport ◽  
Chemical Reduction ◽  
Variable Range Hopping ◽  
Structure And Properties ◽  
Electrical Transport Properties ◽  
One Dimensional ◽  
Temperature Dependence Of Conductivity ◽  
Polyaniline Films ◽  
Dimensional Variable

AbstractAlthough it is well known that the oxidation state of polyaniline is an important characteristic, there are few reports of its influence on the development of morphology and electrical properties in fibers and films. In this work, differential scanning calorimentry is used in conjunction with measurements of temperature dependence of conductivity and thermoelectric power to elucidate the intimate relationship between structure and properties. By increasing the amount of chemical reduction of polyaniline solutions, films are prepared which exhibit a thermal transition between 300 and 385 °C, indicative of melting. Increasing the chemical reduction also increases the conductivity of iodine doped films. The most reduced film exhibited a semiconductor transport mechanism, while the other films could be modeled with a quasi-one dimensional variable range hopping mechanism. The temperature dependence of conductivity also showed increasing order for increasing reduction, consistent with the DSC results.

scholarly journals Electrical Transport Properties ofNi95Ti5Catalyzed Multi wall Carbon Nanotubes Film

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Zishan Husain Khan ◽  
Numan Salah ◽  
Sami Habib
Keyword(s):  
Carbon Nanotubes ◽  
Temperature Region ◽  
Electrical Transport ◽  
Conduction Mechanism ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Multi Wall Carbon Nanotubes ◽  
Variable Range ◽  
Temperature Range ◽  
Dimensional Variable

Carbon nanotubes (CNTs) can be understood as one or more graphite sheets rolled up into a seamless cylinder. CNTs have gained much attention and scientific interest due to their unique properties and potential applications since their discovery in 1991. In the present work, we have deposited Ni95Ti5 film using thermal deposition method. Finally, theNi95Ti5catalyzed multi wall carbon nanotubes (MWNTs) are grown on silicon substrate using low pressure chemical vapor deposition (LPCVD) method and the electrical transport properties of this MWNTs film are studied over a temperature range (284–4K) to explain the conduction mechanism. We have suggested two types of conduction mechanism for the entire temperature range. For the temperature region (284–220K), the conduction is due to thermally activated process, whereas the conduction takes place via variable range hopping (VRH) for the temperature range of (220–4K). The VRH mechanism changes from three dimensions to two dimensions as we move down to the temperature below 50K. Therefore, the data for the temperature region (220–50K) is plotted for three dimensional variable range hopping (3D VRH) model and the two dimensional variable range hopping (2D VRH) for lower temperature range of (50–4K). These VRH models give a good fit to the experimental data. Using these models, we have calculated various interesting electrical parameters such as activation energy, density of states, hopping distance and hopping energy.

HOPPING CONDUCTION IN SiO2 FILMS CONTAINING CLUSTERS OF GROUP-IV ELEMENTS

1996 ◽  
Vol 03 (01) ◽  
pp. 1059-1063 ◽  
Author(s):  
Y. INOUE ◽  
S. HAYASHI ◽  
K. YAMAMOTO
Keyword(s):  
Temperature Dependence ◽  
Electrical Transport ◽  
Dopant Concentration ◽  
Group Iv ◽  
Localized States ◽  
Optical Data ◽  
Hopping Conduction ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Group Iv Elements

SiO 2 films doped with C, Si, and Ge atoms were prepared by an rf cosputtering method and their electrical transport properties were measured. The films show nonohmic conduction with a conductivity increasing drastically with increasing the dopant concentration in the films. The observed temperature dependence of the conductivity obeys the ln σ∝ T −1/4 law, where σ and T are the conductivity and temperature, respectively. This behavior of the conductivity is indicative of the conduction by the variable-range hopping mechanism. Since the previous optical data for the same films indicate the existence of clusters in the films, it is very likely that the hopping is mediated by localized states associated with the clusters.

Temperature dependence of electrical transport properties of La4BaCu5−xCoxO13+δconducting oxide thin films

2016 ◽  
Vol 55 (4S) ◽  
pp. 04EJ08
Author(s):  
Akihiro Tsuruta ◽  
Yusuke Tsujioka ◽  
Yutaka Yoshida ◽  
Ichiro Terasaki ◽  
Norimitsu Murayama ◽  
...  
Keyword(s):  
Thin Films ◽  
Temperature Dependence ◽  
Transport Properties ◽  
Electrical Transport ◽  
Oxide Thin Films ◽  
Electrical Transport Properties

A study on the effects of mixed organic cations on the structure and properties in lead halide perovskites

2020 ◽  
Vol 22 (5) ◽  
pp. 3105-3111 ◽  
Author(s):  
Chao Wu ◽  
Daoyou Guo ◽  
Peigang Li ◽  
Shunli Wang ◽  
Aiping Liu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Single Crystals ◽  
Electrical Transport ◽  
Organic Cation ◽  
Organic Cations ◽  
Structure And Properties ◽  
Electrical Transport Properties ◽  
Halide Perovskites ◽  
A Site ◽  
Lead Halide

Four types of organic cation-mixed single crystals were successfully synthesized by partially substituting A site cations to investigate the effect of organic cations on structure, optical features, thermal stability, and electrical transport properties.

Magnetic and electrical transport properties of Sr2Ti1−xCoxO4 ceramics by sol–gel

2017 ◽  
Vol 31 (17) ◽  
pp. 1750195
Author(s):  
Li Zhang ◽  
Yibao Li ◽  
Zhen Tang ◽  
Yan Deng ◽  
Hui Yuan ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Low Temperatures ◽  
Sol Gel ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Co Doping ◽  
Hopping Model ◽  
Variable Range Hopping Model ◽  
Co Doped

Microstructures, electrical transport and magnetic properties of Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics are investigated. With Co doping, the Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics remain tetragonal structure while the grain size is decreased with doping. Magnetic moment is enhanced with Co doping and ferromagnetism is observed at low temperatures for Co-doped Sr[Formula: see text]TiO[Formula: see text]. The Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] and Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] show semiconductor-like transport properties, which can be well fitted by Mott variable range hopping model. The results will provide an effective route to synthesize Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics as well as to investigate the physical properties.

High Temperature Variable Range Hopping in Heavy Al Implanted 4H-SiC

2016 ◽  
Vol 858 ◽  
pp. 283-286 ◽  
Author(s):  
Antonella Parisini ◽  
Andrea Parisini ◽  
Marco Gorni ◽  
Roberta Nipoti
Keyword(s):  
Electrical Transport ◽  
Room Temperature ◽  
Hole Transport ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Hopping Transport ◽  
Variable Range ◽  
Transmission Electron ◽  
Temperature Variable ◽  
Post Implantation

In this work, we confirm and extend the results of a previous study where a variable range hopping transport through localized impurity states has been found to dominate the electrical transport properties of 3×1020 cm-3 and 5×1020 cm-3 Al+ implanted 4H-SiC layers after 1950-2000 °C post implantation annealing. In this study, samples with longer annealing times have been taken into account. The temperature dependence of these sample conductivity follows a variable range hopping law, consistent with a nearly two-dimensional hopping transport of non-interacting carriers that in the highest doped samples, persists up to around room temperature. This result indicates that the hole transport becomes strongly anisotropic on increasing the doping level. At the origin of this unusual electrical behavior, may be the presence of basal plane stacking faults, actually observed by transmission electron microscopy in one of the 5×1020 cm-3 samples

Temperature dependence of electrical transport properties ofn‐type solar grade polycrystalline silicon

1983 ◽  
Vol 54 (7) ◽  
pp. 3913-3920 ◽  
Author(s):  
P. C. Mathur ◽  
R. P. Sharma ◽  
Renuka Shrivastava ◽  
P. Saxena ◽  
R. K. Kotnala
Keyword(s):  
Temperature Dependence ◽  
Transport Properties ◽  
Electrical Transport ◽  
Polycrystalline Silicon ◽  
Electrical Transport Properties

SYNTHESIS AND CHARACTERIZATION OF COMPLEX FERROELECTRIC OXIDE

2012 ◽  
Vol 02 (04) ◽  
pp. 1250024 ◽  
Author(s):  
PIYUSH R. DAS ◽  
B. N. PARIDA ◽  
R. PADHEE ◽  
R. N. P. CHOUDHARY
Keyword(s):  
Temperature Dependence ◽  
Electrical Transport ◽  
Room Temperature ◽  
Structural Characteristics ◽  
Ferroelectric Properties ◽  
Complex Impedance ◽  
Electrical Transport Properties ◽  
Arrhenius Behavior ◽  
Orthorhombic Crystal ◽  
Grain Distribution

The polycrystalline sample of Li2Pb2Pr2W2Ti4V4O30 was prepared by a solid-state reaction technique. The preparation conditions of the compound have been optimized using thermal analysis (DTA and TGA) technique. Room temperature structural analysis confirms the formation of single phase compound in orthorhombic crystal system. The surface morphology of the sample, recorded by scanning electron microscope, shows uniform grain distribution on the surface of the sample. The observation of hysteresis loop confirmed that the material has ferroelectric properties at room temperature. Electrical properties of the material were studied by complex impedance spectroscopic technique. Temperature dependence of electrical parameters (impedance, modulus, etc.) is strongly correlated to the micro-structural characteristics (bulk, grain boundary, etc.) of the sample. A typical temperature-dependent resistive characteristic of the sample (i.e., negative temperature coefficient of resistance (NTCR)) exhibits its semiconducting properties. The temperature dependence of dc conductivity shows a typical Arrhenius behavior. A signature of ionic conductivity in the system was observed in ac conductivity spectrum. The sample obeys Jonscher's universal power law. The hopping mechanism for electrical transport properties of the system with nonexponential-type conductivity relaxation was suggested from the electrical modulus analysis.

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