Thermal conductivity of hexagonal BC2P - a first-principles study

Rajmohan Muthaiah; Fatema Tarannum; Roshan Sameer Annam; Avinash Singh Nayal; Swapneel Danayat; Jivtesh Garg

doi:10.1039/d0ra08444a

Thermal conductivity of hexagonal BC₂P - a first-principles study

RSC Adv. 2020 Nov 23;10(70):42628-42632. doi: 10.1039/d0ra08444a.

Authors

Rajmohan Muthaiah¹, Fatema Tarannum¹, Roshan Sameer Annam¹, Avinash Singh Nayal¹, Swapneel Danayat¹, Jivtesh Garg¹

Affiliation

¹ School of Aerospace and Mechanical Engineering, University of Oklahoma Norman OK-73019 USA rajumenr@ou.edu.

Abstract

In this work, we report a high thermal conductivity (k) of 162 W m^-1 K^-1 and 52 W m^-1 K^-1 at room temperature, along the directions perpendicular and parallel to the c-axis, respectively, of bulk hexagonal BC₂P (h-BC₂P), using first-principles calculations. We systematically investigate elastic constants, phonon group velocities, phonon linewidths and mode thermal conductivity contributions of transverse acoustic (TA), longitudinal acoustic (LA) and optical phonons. Interestingly, optical phonons are found to make a large contribution of 30.1% to the overall k along a direction perpendicular to the c-axis at 300 K. BC₂P is also found to exhibit high thermal conductivity at nanometer length scales. At 300 K, a high k value of ∼47 W m^-1 K^-1 is computed for h-BC₂P at a nanometer length scale of 50 nm, providing avenues for achieving efficient nanoscale heat transfer.