Heat transfer mechanisms quantified at submicron scales in scanning thermal microscopy

Abstract

This work investigates the heat transfer between scanning thermal microscopy (SThM) probes and samples. It presents a detailed study of the heat transfer mechanisms that operate between the probe and the sample. Two SThM resistive probes of different sizes were used in active mode. Depending on the experimental conditions, the heat transferred to the sample through water meniscus, solid-solid contact and air is quantified. The methodology established to estimate the heat conduction through water meniscus shows that this mechanism is not dominant in the tip-sample heat exchange. Based on experimental results of measurements performed under vacuum conditions, the thermal boundary resistance at different contacts is estimated and in accordance with literature values. Through measurements performed under ambient conditions, the heat conduction through air appears to be strongly dependent on the sample thermal conductivity.