We have experimentally investigated the heat transfer mechanisms at a 90±10 nm diameter point contact between a sample and a probe tip of a scanning thermal microscope (SThM). For large heated regions on the sample, air conduction is the dominant tip-sample heat transfer mechanism. For micro/nano devices with a submicron localized heated region, the air conduction contribution decreases, whereas conduction through the solid-solid contact and a liquid meniscus bridging the tip-sample junction become important, resulting in the sub-100 nm spatial resolution found in the SThM images. Using a one dimensional heat transfer model, we extracted from experimental data a liquid film thermal conductance of 6.7±1.5 nW/K. Solid-solid conduction increased linearly as contact force increased, with a contact conductance of and saturated for contact forces larger than 38±11 nN. This is most likely due to the elastic-plastic contact between the sample and an asperity at the tip end.
Thermal Transport Mechanisms at Nanoscale Point Contacts
Contributed by the Heat Transfer Division for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received by the Heat Transfer Division February 8, 2001; revision received July 27, 2001. Associate Editor: D. Poulikakos.
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Shi , L., and Majumdar, A. (July 27, 2001). "Thermal Transport Mechanisms at Nanoscale Point Contacts ." ASME. J. Heat Transfer. April 2002; 124(2): 329–337. https://doi.org/10.1115/1.1447939
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