High-Pressure Synthesis and Thermal Transport Properties of Polycrystalline BAsx**Supported by the National Key R&D Program of China (Grant Nos. 2018YFE0103200 and 2018YFA0305700), the National Natural Science Foundation of China (Grant Nos. 51772324, 11934017, 11921004, and 11574378), and the Chinese Academy of Sciences (Grant Nos. QYZDB–SSW–SLH013 and GJHZ1773).

Abstract

Polycrystalline BAsx (x = 0.80–1.10) compounds with different boron-to-arsenic elemental molar ratios were synthesized by a high-pressure and high-temperature sintering method. Compared with other ambient-pressure synthesis methods, high pressure can significantly promote the reaction speed as well as the reaction yield. As the content of arsenic increases from x = 0.91 to 1.10, the thermal conductivity of BAsx gradually increases from 53 to 65 W⋅m−1⋅K−1. Furthermore, the temperature dependence of thermal conductivities of these samples reveals an Umklapp scattering due to the increasing phonon population. This work provides a highly efficient method for polycrystalline BAs synthesis.