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electric-resistance-measurement
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Self aligned passivation of Cu in Cu/Cr, Cu/V and Cu/Ta multilayers
, Article 12th International Conference on Microelectronics, ICM 2000, 31 October 2000 through 2 November 2000 ; Volume 2000-October , 2000 , Pages 209-212 ; 9643600572 (ISBN) ; Vashaei, Z ; Mahdavi, S. M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2000
Abstract
We compare Cu/M/SiO2 (M=Cr,V and Ta) multilayers that were deposited on Si substrates. Sample resistance measurements were carried out during annealing in 80% N2+20% H2, N2 and Ar environments. Resistivity measurements, SEM observations, RBS and AES spectroscopies from annealed samples showed good diffusion barrier properties for Cr and V but rather poor properties for Ta buffer layers. This is due to the amorphous nature of Cr films and formation of a continuous Cu overlayer. SEM observation also showed granular structure for Cu/V and Cu/Ta with grain sizes of about 500 and 1000 Å respectively. However, shallow nitrogen implantation in Cu/V samples and DC biasing for Cu/Ta layers during...
Data acquisition and resistance measurements using a simple program
, Article Scientia Iranica ; Volume 14, Issue 5 , 2007 , Pages 467-473 ; 10263098 (ISSN) ; Azimi, P ; Poseh, G. H ; Sharif University of Technology
Sharif University of Technology
2007
Abstract
The goal of this paper is to describe a simple method for the automated data acquisition and analysis of data taken by programmable instruments. Device controls and communication method are explained and some typical illustrative examples showing the potential applications of the method in real experiments are presented. This method offers a quick and flexible way to control many instruments by using a multi-device arrangement of a stacking method in a parallel operation. The General-Purpose Interface Bus (GPIB) is used here for remote control of the devices. By using Excel and Visa interactive programs and using GPIB interface, easy communication and data transfer between instruments and a...
SnO2/ZnO double layer thin films: A novel economical preparation and investigation of sensitivity and stability of double layer gas sensors
, Article International Journal of Nanomanufacturing ; Volume 2, Issue 1-2 , 2008 , Pages 59-69 ; 17469392 (ISSN) ; Shokuhfar, A ; Sadrnezhaad, S. K ; Shokuhfar, T ; Sharif University of Technology
Inderscience Publishers
2008
Abstract
A double-layer SnO2/ZnO gas sensor was produced by utilisation of SnOSUB align=right2 and ZnO thin films. Top layer consisted of SnOSUB align=right2 produced by a sol gel-controlled annealing technique. Bottom coating consisted of ZnO thin film precipitated by Two-Stage Chemical Deposition (TSCD) from an aqueous zinc-containing solution. Both top and bottom coatings were analysed by SEM, XRD, EDAX and AAS. Gas sensitivity of the SnO2/ZnO double layer was determined by electrical resistance measurements. Although sensitivity was slightly reduced by double-layer formation, selectivity and stability were considerably improved by combination of the two thin layers. The existence of an...
Effect of Sr/Ba substitution in Gd1-xPrxBaSrCu 3O7-δ
, Article Physica C: Superconductivity and its Applications ; Volume 423, Issue 3-4 , 2005 , Pages 163-174 ; 09214534 (ISSN) ; Akhavan, M ; Sharif University of Technology
2005
Abstract
Tetragonal Gd1-xPrxBaSrCu3O 7-δ (0 ≤ x ≤ 1) polycrystalline samples have been prepared by the standard solid-state reaction, and characterized by XRD and SEM. Resistance measurements and XRD patterns show site mixing between rare earth R and Sr is less than R and Ca. Contrary to Gd1-xPrxBa 2Cu3O7-δ, a hump on the ρ(T) curve is observed at about 80 K. Based on the resistivity measurements, the effect of Pr substitution in the 1113 structure, in comparison with the 123 structure, on the increase of pseudogap temperature is investigated. The normal state resistivity has been analyzed by the two and three dimensional variable range hopping (2D-VRH and 3D-VRH) and Coulomb gap. For the low...
Characterization of constrained aged niti strips for using in artificial muscle actuators
, Article International Journal of Engineering, Transactions A: Basics ; Volume 24, Issue 4 , 2011 , Pages 321-329 ; 17281431 (ISSN) ; Sadrnezhaad, S. K ; Sharif University of Technology
Abstract
Marvelous bending/straightening effects of two-way shape memory alloy (TWSMA) help their employment in design and manufacturing of new medical appliances. Constrained ageing with bending load scheme can induce two-way shape memory effect (TWSME). Scanning electron microscopic (SEM) analysis, electrical resistivity measurement (ERM) and differential scanning calorimetry (DSC) are employed to determine the property change due to flat strip constrained aging. Results show that flat-annealing prior to the aging shifts NiTi transformations temperatures to higher values. Superelastic behavior of the as-received/flat- annealed/aged samples with more adequate transition temperatures due to...
Hydrogen sensing properties of multi-walled carbon nanotube films sputtered by Pd
, Article International Journal of Hydrogen Energy ; Volume 35, Issue 9 , 2010 , Pages 4445-4449 ; 03603199 (ISSN) ; Mortazavi, S. Z ; Iraji zad, A ; Rahimi, F ; Sharif University of Technology
Abstract
Multi-Walled Carbon nanotube (MWCNTs) films were obtained by Thermal Chemical Vapor Deposition method and coated by palladium sputtering process. Raman spectroscopy was used to study alteration in quality of the carbon nanotubes after the sputtering process. Fourier Transform Infra Red (FTIR) spectroscopy showed that hydrogenation process can reduce the C{double bond, long}O to C-O and also produce O-H bond. Furthermore, the electrical resistance measurement for Pd/MWNTs films was performed in a chamber with 1% hydrogen gas in a constant dry air flow. Hydrogen sensing behavior of the films was investigated at 50 °C. Pd/MWCNTs films presented an irreversible gas response to hydrogen in the...
Characterization of sputtered NiTi shape memory alloy thin films
, Article Scientia Iranica ; Volume 16, Issue 3 B , 2009 , Pages 248-252 ; 10263098 (ISSN) ; Naderi, M ; Zare Bidaki, H ; Sadrnezhaad, Kh ; Sharif University of Technology
2009
Abstract
During recent years, many investigations have been carried out to determine how to select different materials for the making of Micro Electro Mechanical Systems (MEMS) and bio-MEMS. The NiTi shape memory alloy thin film has been much regarded as a promising candidate for MEMS due. to its unique shape memory effect and high energy output. In this research, NiTi thin film was fabricated using a sputtering technique from separate elemental Ni and Ti targets. The characterizations of the deposited films were, investigated using different analysis techniques, such as Field Emission SEM, DSC, XR.D, electrical resistivity measurement and nanoindentation. © Sharif University of Technology, June 2009...
Silver nanowires immobilized on gold-modified glassy carbon electrode for electrochemical quantification of atorvastatin
, Article Journal of Electroanalytical Chemistry ; Volume 876 , November , 2020 ; Hormozi Nezhad, M. R ; Shahrokhian, S ; Asadian, E ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Development of simple yet precise sensing platforms for rapid determination of biological species and drugs is of paramount importance, not only for analysis of pharmaceutical formulations during the production stage, but also in clinical practices and medical diagnosis. In the present research, we report on the electrochemical determination of atorvastatin (ATOR) by using silver nanowires/gold-modified glassy carbon electrode (Ag NWs/Au/GCE). The modified electrode was constructed through a two-step procedure in which narrow silver nanowires synthesized via a polyol method are drop casted on a pre-modified GCE with electrodeposited gold particles. The results of XRD analysis indicated the...