Fig. 1
From: Non-monotonic pressure dependence of the thermal conductivity of boron arsenide
Phonons and thermal conductivity of MgO and cBN under pressure. a Phonon dispersions for MgO at 300 K computed at 0 GPa (black) and 35 GPa (red) pressures. The calculations are in good agreement with the measurements of phonon frequencies at 0 GPa32,33 and 35 GPa34. b Three-phonon and 3 + 4-phonon limited κ of MgO versus pressure at 300 K compared with experiments9. c Three-phonon and 3 + 4-phonon limited κ of cBN (red curves: isotopically pure 11B14N, black curves: naturally occurring cBN) versus pressure at 300 K. Our results for cBN differ from those in ref. 46, where a bimodal behavior of the three-phonon limited κ for cBN with increasing pressure was observed, but was later identified18 to be erroneous and related to required symmetries of the inter-atomic force constants used in ref. 46 not being satisfied
