Sina’s research published in Applied Physics Letters
Sina Hamian has published in Applied Physics Letters. The title of his publication is “Quantitative Probing of Tip-Induced Local Cooling with a Resistive Nanoheater/Thermometer”. Abstract: This article reports the investigation of tip-induced local cooling when an atomic force microscope (AFM) cantilever tip scans over a joule-heated Pt nanowire. We fabricated four-point-probe Pt resistive nanothermometers having a sensing area of 250nm×350nm by combining electron-beam lithography and photolithography. The electrical resistance of a fabricated nanothermometer is ~27.8Ω at room temperature, and linearly proportional to the temperature increase up to 350K. The equivalent temperature coefficient of resistance is estimated to be K-1. We also joule-heated a nanothermometer to increase its sensing area temperature up to 338.50.2K, demonstrating that the same device can be used as a nanoheater. An AFM probe tip scanning over a heated nanoheater/thermometer’s sensing area induces local cooling due to heat conduction through solid-solid contact, water meniscus, and surrounding air. The effective contact thermal conductance is 32.5±0.8nW/K. These results contribute to the better understanding of tip-substrate thermal interactions, which is the fundamental subject in tip-based thermal engineering applications.