Crystal structures and metastability of carbon-boron compounds C3B and C5B

SuperhardBC3in Cubic Diamond Structure

“…Also shown in Fig. 2(a) is the enthalpy of a recently proposed R3m structure [12], which is energetically more favorable than all the predicted sp 3 bonded structures. However, this R3m structure contains a mixture of sp 2 and sp 3 bonding, which is in contrast to the exclusively sp 3 bonding nature of the synthesized diamondlike BC 3 [6].…”

“…Electron energy loss spectroscopy (EELS) measurements show that this c-BC 3 is a single phase with all the atoms forming a sp 3 bonding network. Several structural models have been proposed for c-BC 5 and c-BC 3 [7][8][9][10][11][12]; however, they all suffer from incorrect crystal symmetry and even wrong bonding character compared to the experimentally observed diamondlike cubic structure with all the atoms in the sp 3 bonding state. This lack of an accurate structural determination impedes further understanding and exploration of these novel B-C compounds, and it calls for an innovative approach to solving such complex crystal structures.…”

“…Boron and carbon have similar atomic radii, mak- ing site disorder a possibility in boron carbides [5,12]. We have simulated disordered BC 3 alloys using a special quasirandom structure (SQS) model [45,46] for the distribution of boron and carbon atoms in fully relaxed diamond-lattice-based n-atom (n = 16, 32, 64, and 128) supercells [26].…”

Pressure effect on structural, elastic, and thermodynamic properties of tetragonal B4C4

“…[11][12][13][14][15][16] On the theoretical side, several state-of-the-art structure prediction theoretical approaches based on different algorithms have been applied to predict and design new B-C materials to complement experiments. 12,13,[16][17][18] One of the most successful examples is the structural determination of the newly synthesized cubic BC 3 (c-BC 3 ) using an unbiased swarm structure search, 18 the simulated x-ray diffraction and Raman peaks of predicted c-BC 3 phase with a large 64-atom unit cell are in excellent agreement with experimental data.…”

The Elastic Anisotropic and Thermodynamic Properties of I4mm-B3C

“…Liu et al [10] have explored the crystal structures of synthesized diamond-like BC 3 (d-BC 3 ) with particle swarm optimization (PSO) algorithm, and found that the simulated Raman modes of P mma phase are in agreement with the experimental data. Recently, Mikhaylushkin et al [11] predicted two stable boron carbides (BC 3 and BC 5 ) and found they are more stable than those previously reported. Li et al [12] found that the hardness of the B-C system has a decreasing trend with the increase of boron concentration.…”