TY - JOUR
T1 - Structural, electronic and mechanical properties of sp3-hybridized BN phases
AU - Zhou, Rulong
AU - Dai, Jun
AU - Cheng Zeng, Xiao
N1 - Funding Information:
This work is supported by the National Natural Science Foundation of China (Grant No. 11104056), NSAF (Grant No. U1630118). XCZ is supported by a Qianren-B fund (1000 Talents Plan B for summer research) from USTC and a State Key R&D Fund of China (2016YFA0200604) to USTC. The numerical calculations are supported by the supercomputing system in the Supercomputing Center of University of Science and Technology of China, and the University of Nebraska Holland Computing Center. We thank Professor Davide M. Proserpio who offered to examine whether our BN structures could be found in an on-line database of carbon allotropes (SACADA: http://sacada.sctms. ru/). Professor Davide M. Proserpio pointed out thatM21W1 appears to be a new structure for carbon allotrope.
Publisher Copyright:
© the Owner Societies 2017.
PY - 2017
Y1 - 2017
N2 - Motivated by the discovery of new phases of carbon under cold high-pressure compression, we performed a global structure search of high-pressure phases of boron nitride (BN). Ten new bulk phases were identified, each energetically more stable than the graphite-like hexagonal BN (h-BN) under high pressures. All ten high-pressure phases could be viewed as involving a stacking of buckled h-BN layers. Some of these solid structures can be fabricated through the cold high-pressure compression of h-BN films. According to the buckling of the h-BN layers, the new BN phases could be classified into three groups. The atomic structures, relative stabilities, electronic structures, and mechanical properties were studied in detail. A strong dependence of the relative stability, band structure, and mechanical properties on the buckling of h-BN was observed. The computed electronic band structures suggested that most of the high-pressure BN phases were insulators with wide and indirect band gaps. The calculated elastic constants and hardness suggested that several of the BN structures were superhard materials with potential applications in materials science and engineering. The computed transition paths indicated that the direct transition from h-BN to four of the new sp3-hybridized BN structures, or specifically to w-BN or bct-BN, were likely to occur through cold compression. For the other five of the new BN structures, although deeper local minima existed in the transition path, their formation through cold compression of h-BN was still plausible due to the low transition barrier from the deeper local minima to the targeted structure.
AB - Motivated by the discovery of new phases of carbon under cold high-pressure compression, we performed a global structure search of high-pressure phases of boron nitride (BN). Ten new bulk phases were identified, each energetically more stable than the graphite-like hexagonal BN (h-BN) under high pressures. All ten high-pressure phases could be viewed as involving a stacking of buckled h-BN layers. Some of these solid structures can be fabricated through the cold high-pressure compression of h-BN films. According to the buckling of the h-BN layers, the new BN phases could be classified into three groups. The atomic structures, relative stabilities, electronic structures, and mechanical properties were studied in detail. A strong dependence of the relative stability, band structure, and mechanical properties on the buckling of h-BN was observed. The computed electronic band structures suggested that most of the high-pressure BN phases were insulators with wide and indirect band gaps. The calculated elastic constants and hardness suggested that several of the BN structures were superhard materials with potential applications in materials science and engineering. The computed transition paths indicated that the direct transition from h-BN to four of the new sp3-hybridized BN structures, or specifically to w-BN or bct-BN, were likely to occur through cold compression. For the other five of the new BN structures, although deeper local minima existed in the transition path, their formation through cold compression of h-BN was still plausible due to the low transition barrier from the deeper local minima to the targeted structure.
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U2 - 10.1039/c7cp01302g
DO - 10.1039/c7cp01302g
M3 - Article
C2 - 28358407
AN - SCOPUS:85020027199
SN - 1463-9076
VL - 19
SP - 9923
EP - 9933
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 15
ER -