Nanoscale heat transfer at contact between a hot tip and a substrate

Abstract

Hot tips are used either for characterizing nanostructures by using Scanning Thermal Microscopes or for local heating to assist data writing. The tip-sample thermal interaction involves conduction at solid-solid contact as well as conduction through the ambient gas and through the water meniscus. We analyze those three heat transfer modes with experimental data and modeling. We conclude that the three modes contribute in a similar manner to the thermal contact conductance but they have distinct contact radii ranging from 30nm to 1micron. We also show that any scanning thermal microscope has a 1 to 3 microns resolution when used in ambient air.

Novel Measurement Methods for Thermoelectric Power Generator Materials and Devices

“…ρ 0 and κ P are the probe's electrical resistivity and thermal conductivity, respectively, TCR is the probe's temperature coefficient of resistance, I is root-mean-square electrical current passed through the probe, and r is the radius of the probe. Contribution from radiation is negligible for ΔT < 100 K [13]. To obtain an analytical solution to the second order differential equation, two boundary conditions are employed.…”

Scanning Thermal Microscopy (SThM)

“…To enable optical feedback for AFM topography measurement, a mirror is placed on top of the wires (see Figure 9a). For their simple, almost macroscopic design, Wollaston-wire probes have often been used to investigate the thermal contact between the tip and the sample (Gomès et al, 2001;Lefèvre, Volz, Saulnier, Fuentes, & Trannoy, 2003, Lefèvre, Volz, & Chapuis, 2006. However, the disadvantages, which are low spatial resolution and complicated fabrication process, were significant enough to find a new way to utilize resistor-based probes in SThM measurements.…”

“…The general idea behind the RBTR method is to find the shape of the largest possible tip that could have been used to produce the analyzed topography image. Because the details on tip-sample thermal contact play a crucial role in the analysis of any SThM results, many approaches to the analysis of phenomena occurring between the probe and the sample surface have been proposed, all of them being a combination of experiment, analytical analysis, and simulation (Luo, Shi, Varesi, & Majumdar, 1997;Gomès et al, 2001;Lefèvre et al, 2006;Thiery et al, 2008;Bodzenta et al, 2010;Tovee et al, 2012;Gotsmann & Lantz, 2013;Kim et al, 2014). Moreover, all of these works included some assumptions about the tip shape, which often turned out to have a significant impact on the conclusions.…”

A piezo-thermal probe for thermomechanical analysis

“…22,23 The main mechanism of heat transfer from the tip to the substrate is by conduction. 15,22,[26][27][28] In our case the tip is covered with a thin film of gold, which has a thermal conductivity of 318 W/mK. The thermal conductivity of naphthalene is 0.12 W/mK.…”