A review about the surface resistance technique in electrochemistry

Resistivity and Hall effect of copper films before and after adsorption of carbon monoxide

We study the generation of thermoelectricity by nanoscale thermocouples (TCs) formed from a single layer of metal with cross-sectional discontinuity. Typically, a TC is formed when a second conductor is inserted between two sections of a first conductor forming two junctions situated at different temperatures. Here, we investigate the behavior of TCs formed not of two conductors but rather nanowires of the same metal of two cross-sectional areas. Monometallic TCs were constructed from a lithographically defined nanowire having one abrupt variation in width along its length, and tested at room temperature; these structures exploit a change in Seebeck coefficient that is present at these size scales. To investigate the thermoelectric properties of such “shape-engineered” TCs, nanoscale heaters were employed to set the local temperatures. Temperature profiles at the hot and cold junctions of the TCs were determined both by simulations and experiments. Results demonstrate that the magnitude of the open-circuit voltage, and hence the relative Seebeck coefficient, is a function of the parameters of the variations in the segment widths. The fabrication complexity of such shape-engineered monometallic nanowire TCs is greatly reduced compared to that of conventional bimetallic TCs, and could be mass-produced using simpler manufacturing techniques.

Single-Metal Nanoscale Thermocouples

The behavior of a pressure transducer with Au-Ni (89:11) film as strain gauges has been studied. The effects of postdeposition heat treatment on the resistance of the thin-film strain gauges and hence the output performance of the pressure transducer are discussed. The effect of a repeated number of pressure cycles carried out over a period of eight months has also been reported. The maximum nonlinearity and the hysteresis is improved from 0.92% FSO to 0.06% FSO after 1000 pressure cycles. The output behavior of the pressure transducer with temperature has also been studied. >

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G.C. Jain

Papers

Size effect in the electrical conductivity and seebeck coefficient in thin metallic films

Size effect in longitudinal and transverse strain coefficient of resistance in silver films

Low field magnetoresistance and hall effect in thin metallic films