P213 BN: a novel large-cell boron nitride polymorph

Qing-Yang Fan(樊庆扬),Nan Wu(吴楠),Shuai-Ming Chen(陈帅铭),Li Jiang(江莉),Wei Zhang(张伟),Xin-Hai Yu(于新海),Si-Ning Yun(云斯宁)

Table 3. Density (g/cm3), anisotropic sound velocities (m/s), average sound velocity (m/s) and Debye temperature (K) for P213 BN, Pm-3n BN, and c-BN.

Propagation direction Propagation direction P213 BN Pm-3n BN c-BN ρ 2.190 2.820 3.467 [111] [111]vl 14174 24597 28887 [11-2]vt12 4309 9870 10095 [110] [110]vl 8165 14605 16272 [1-11]vt1 6044 14768 13308 [001]vt2 5406 5490 6899 [100] [100]vl 8109 15756 14990 [010]vt1 4379 8609 11342 [001]vt2 4379 8609 11342 vl 8154 14767 15947 vt 4332 9298 10527 vm 4841 10235 11522 ΘD 684 1572 1896