Thermal Expansion Coefficient and Lattice Anharmonicity of Cubic Boron Arsenide
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2019-06-28 |
| Journal | Physical Review Applied |
| Authors | Xi Chen, Chunhua Li, Fei Tian, Geethal Amila Gamage, Sean E. Sullivan |
| Institutions | The University of Texas at Austin, University of Houston |
| Citations | 34 |
Abstract
Section titled āAbstractāRecent measurements of an unusual high thermal conductivity of around 1000 W\nm-1 K-1 at room temperature in cubic boron arsenide (BAs) confirm predictions\nfrom theory and suggest potential applications of this semiconductor compound\nfor thermal management applications. Knowledge of the thermal expansion\ncoefficient and Gr\āuneisen parameter of a material contributes both to the\nfundamental understanding of its lattice anharmonicity and to assessing its\nutility as a thermal-management material. However, previous theoretical\ncalculations of the thermal expansion coefficient and Gr\āuneisen parameter of\nBAs yield inconsistent results. Here we report the linear thermal expansion\ncoefficient of BAs obtained from the X-ray diffraction measurements from 300 K\nto 773 K. The measurement results are in good agreement with our ab initio\ncalculations that account for atomic interactions up to fifth nearest\nneighbours. With the measured thermal expansion coefficient and specific heat,\na Gr\āuneisen parameter of BAs of 0.84 +/- 0.09 is obtained at 300 K, in\nexcellent agreement with the value of 0.82 calculated from first principles and\nmuch lower than prior theoretical results. Our results confirm that BAs\nexhibits a better thermal expansion coefficient match with commonly used\nsemiconductors than other high-thermal conductivity materials such as diamond\nand cubic boron nitride.\n