Electronic Transport in Tin(IV) Oxide Nanocrystalline Films: Two-Medium Transport with Three-Dimensional Variable-Range Hopping Mechanism for the Ultrasmall Nanocrystallite Size Regime

2011 ◽  
Vol 116 (8) ◽  
pp. 4979-4985 ◽  
Author(s):  
Samad Bazargan ◽  
Nina F. Heinig ◽  
Jose Fernando Rios ◽  
K. T. Leung
1993 ◽  
Vol 07 (03) ◽  
pp. 163-169 ◽  
Author(s):  
R. FEDUZI ◽  
F. LANZA ◽  
V. DALLACASA

The resistivity of Li doped CuO polycrystalline samples is discussed following the variable-range hopping mechanism (VRH) form, exp ((T0/T)1/4), between 80 and 300 K. The T0 have been measured to be in the range of 107 − 108 K . In the CuO undoped system, the VRH mechanism does not fit appreciably the resistivity data in the range of temperature considered. However, when Li is introduced, this behaviour is followed, leading us to suggest that the Li doped CuO could be view as a disordered system. At higher temperatures, the thermal activation mechanism takes place.


2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Zishan Husain Khan ◽  
Numan Salah ◽  
Sami Habib

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.


1997 ◽  
Vol 56 (3) ◽  
pp. 1161-1169 ◽  
Author(s):  
F. W. Van Keuls ◽  
X. L. Hu ◽  
H. W. Jiang ◽  
A. J. Dahm

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3338-3341
Author(s):  
V. Ta Phuoc ◽  
R. De Sousa ◽  
L. Ammor ◽  
J. C. Soret ◽  
A. Ruyter ◽  
...  

We report on vortex transport in Bi2Sr2Ca 1-x Y x Cu2O8 crystals irradiated at different doses of heavy ions. We show evidence of a flux-creep resistivity typical of a variable-range vortex hopping mechanism as predicted by Nelson and Vinokur.


Sign in / Sign up

Export Citation Format

Share Document