Temperature dependent resistivity of platinum-carbon composite nanowires grown by focused ion beam on SiO2/Si substrate
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Colleges, School and Institutes
Experimental studies of the temperature dependent resistivity of platinum nanowires grown on an oxidised silicon wafer by using focused ion beam (FIB) have been made. A series of 4-terminal resistivity measurements were carried out in the temperature range 50-300 K on single nanowires of width and thickness similar to 100 nm grown by decomposition of an organometallic precursor using Ga+ ions of different accelerating voltages from 10 key to 30 key. Energy dispersive X-ray spectroscopy showed the nanowires to be composed of more than 60% by volume of carbon, the remainder being principally platinum and gallium. The exact composition depends on the accelerating voltage of the ions used. There is clear evidence from cross-sectional microscopy that the material is a composite consisting of a metallic phase present in the form of nanoscale clusters, randomly distributed in a matrix of carbon. Electrical measurements are consistent with this, showing a critical volume concentration for conduction, which is typical of electron transport in composites with percolating metal phase. Results show an unexpectedly high sensitivity of the temperature dependence of resistivity near the critical volume concentration, which has been explained to arise from thermal strain effects. The anomalous temperature/strain effects observed in this investigation might be exploited in temperature measurement and strain sensor applications. (C) 2011 Elsevier B.V. All rights reserved.
|Number of pages||5|
|Publication status||Published - 1 Nov 2011|
- Percolation, Focused ion beam, Platinum nanowire