Session: Research Posters

Paper Number: 114177

114177 - A Precise Method to Characterize Thermal Transport Properties of Two-Dimensional Ferromagnetic Materials 

Two-dimensional (2D) materials have been extensively studied and exploited in various fields such as electronics, sensors, bioengineering, energy storage, magnetism, and conversion technology due to their excellent electronic, optical, and thermal properties. Specifically, in recent years, they become emergent thermal and thermoelectric materials with the potential widespread in wearable devices applications. Recently, 2D ferromagnetic materials have started to gain numerous interests due to their unique and superior magnetic properties. However, due to their easiness to oxidize in air, it is challenging to precisely characterize their thermal transport properties.

In this work, 2D ferromagnetic materials Fe3GeTe2 is studied. Fe3GeTe2 was coated by a thin layer of transparent polymer to prevent oxidation. Then, opto-thermal Raman method was used to study their thermal properties. We first utilize more direct measurements of the optical absorption, and then by comparing the response of the samples using different laser spot sizes, we are able to measure the thermal conductivities.

The Raman opto-thermal technique has been the most successful method for the measurement of thermal conductivity of 2D materials and was used to measure the 2D materials at large mechanical strains for the first time in this work. In this technique, a laser is focused at the center of a thin film and used to measure the peak position of a Raman-active mode. As the laser power is increased, the sample is heated which enables red-shift Raman mode due to thermal softening. Another group of experiments is conducted by placing the samples on a heating platform and monitoring the change of Raman-active mode peak position shift. Combining these two sections of experiments provides us with the thermal modeling that can then be used to extract the thermal conductivity from the measured shift rate. We have used a refined version of the opto-thermal Raman technique to study the thermal conductivity of 2D materials, at large mechanical strains. It is the first thermal measurement on 2D ferromagnetic materials.

In conclusion, we have used Raman opto-thermal technique to study the thermal transport properties of 2D Fe3GeTe2 specifically in sub-nm thickness. This work addresses several important issues in the measurement of thermal conductivity of 2D ferromagnetic materials using Raman spectroscopy. We derive the thermal conductivity values at room temperature and in air. These results are of significance to discovering the thermal transport properties of 2D ferromagnetic materials, and thus develop an efficient thermal characterization method for the materials and devices that are unstable in air.

Presenting Author: Xian Zhang Stevens Institute of Technology

Presenting Author Biography: Assistant professor at Stevens Institute of Technology.

Authors:

Elham Easy Stevens Institute of Technology
Isabella Disturco Stevens Institute of Technology
Xian Zhang Stevens Institute of Technology