NYCU ME
Student Speaker: Wei-Tsu Peng
Title: Thermal Conductivity and Electrical Resistivity of a Single Metal Nanowire
Date: 2021/06/03 (Thursday) 3:30 pm – 5:20pm
Location: video conference
Abstract:
To enhance the efficiency of the electronic device, products miniature is a tendency for which can lower the cost and save more space. As a result, metal nanowires are commonly used. Copper nanowire (CuNW) is mainly applied to the interconnect, acting as the path for the thermal and electrical transport. It is the connection between the circuit elements, such as transistors and diodes, etc. On the other hand, nickel nanowire (NiNW) is a potential candidate for embedded in the magnetoresistive random access memory (MRAM). However, an urgent issue of heat accumulation, which comes from the higher Joule heat due to size scaling down, is emerging. If the device dissipates heat inefficiently, the rising local temperature will deteriorate the ability of the electronic device. Thus, a well understanding of the thermal conductivity and electrical resistivity of nanowires provides an opportunity to avoid impropriate layout of the electronic device. In this study, the thermal conductivity and electrical resistivity of single CuNWs and NiNWs were investigated at temperature ranging from 30K to 300K. Compared to bulk value, an obvious reduction of thermal conductivity and increment of electrical resistivity for nanowires were obtained. The BlochGrüneisen formula and the unified thermal resistivity were introduced to understand the phonon scattering of the nanowires. Stronger phonon-electron interaction were found in the nanowires, indicating higher interference existing in the nanowires. In addition, the external magnetic field was applied to acquire the thermal conductivity of magnon. The thermal conductivity of magnon accounted for 42%, which is, to our best knowledge, the highest magnon contribution so far.