April 22 - 26, 2024
Seattle, Washington
May 7 - 9, 2024 (Virtual)

Event Supporters

2024 MRS Spring Meeting
EN07.06.04

Thermal Conductivity of 2H and 2H3R Niobium Diselenide Polymorphs

When and Where

Apr 24, 2024
9:30am - 9:45am
Room 327, Level 3, Summit

Presenter(s)

Co-Author(s)

Sungjin Park1,Kyomin Kim2,Kwangrae Kim1,Jong-wook Roh3,Aloysius Soon1,Wooyoung Lee1,Woochul Kim1

Yonsei University1,LIG Nex12,Kyungpook National University3

Abstract

Sungjin Park1,Kyomin Kim2,Kwangrae Kim1,Jong-wook Roh3,Aloysius Soon1,Wooyoung Lee1,Woochul Kim1

Yonsei University1,LIG Nex12,Kyungpook National University3
Niobium diselenide(NbSe<sub>2</sub>) is a two-dimensional van der Waals material whose 2H3R polymorph was discovered recently [1]. The 2H3R polymorph of NbSe<sub>2</sub> possesses a different stacking sequence when compared to the 2H polymorph due to the weak van der Waals bonding between the layers and therefore possesses different physical properties. Previous research has shown that difference in stacking sequence in two-dimensional materials can alter their electrical and thermal properties [1,2]. In this work the thermal conductivity of the 2H and 2H3R polymorphs of NbSe<sub>2</sub>was measured and compared. The in-house T-bridge method was used in the measurement of thermal conductivity [3]. The T-bridge method measures the thermal conductivity of a sample through difference in heat conduction from a suspended heater to a heatsink. NbSe<sub>2</sub> samples of various thicknesses were prepared for both polymorphs. Measured thermal conductivity results showed that the 2H3R polymorph shows lower thermal conductivity compared to the 2H counterpart of similar thickness. Theoretical calculation was performed to study the cause of the difference in thermal conductivity and revealed that the lower thermal conductivity of the 2H3R polymorph was induced by the greater phonon-phonon scattering of the 2H3R polymorph than that of the 2H polymorph.<br/>[1] H. Moon, J. Kim, J. Bang, S. Hong, S. Youn, H. Shin, J.W. Roh, W. Shim, W. Lee, <i>Nano Energy</i> <b>78</b>, 105197 (2020)<br/>[2] P. Erhart, P. Hyldgaard, D. O. Lindroth, <i>Chemistry of Materials</i> <b>27</b>, 551-5518 (2015)<br/>[3] J. Kim, D. J. Seo, H. Park, H. Kim, H. J. Choi, W. Kim, <i>Review of Scientific Instruments</i> <b>88</b>, 054902 (2017)

Keywords

thermal conductivity

Symposium Organizers

Woochul Kim, Yonsei University
Sheng Shen, Carnegie Mellon University
Sunmi Shin, National University of Singapore
Sebastian Volz, The University of Tokyo

Session Chairs

Yee Kan Koh
Jaeyun Moon

In this Session