【摘 要】
：
The structural,mechanical,electronic,mechanical anisotropy,and thermal properties of boron nitride (BN) polymorphs,such as B4N4-Ⅰ and B4N4-Ⅱ,are investigated
【机 构】
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Key Laboratory of Civil Aircraft Airworthiness Technology, Civil Aircraft Airworthiness and Repair K
论文部分内容阅读
The structural,mechanical,electronic,mechanical anisotropy,and thermal properties of boron nitride (BN) polymorphs,such as B4N4-Ⅰ and B4N4-Ⅱ,are investigated under ambient pressure utilizing first-principles generalized gradient approximation calculations using an ultrasoft pseudopotential scheme.The phonon spectra and elastic constants reveal that B4N4-Ⅰ is dynamically and mechanically stable at the pressure of 0 GPa and temperature of 0 K.Anisotropic calculations indicate that both B4N4-Ⅰ and B4N4-Ⅱ exhibit higher anisotropy of Young’s modulus than cubic BN (c-BN).B4N4-Ⅱ and B4N4-Ⅰ present indirect and wide band gaps of 5.32 eV and 4.86 eV,respectively.In addition,B4N4-Ⅰ is more brittle than B4N4-Ⅱ.Moreover,the minimum thermal conductivity,κmin,of B4N4-Ⅱ at 300 K is 1.92 W/(cm·K),which is slightly higher than those of B4N4-Ⅰ and c-BN (1.84 W/(cm·K) and 1.83 W/(cm·K),respectively.However,κmin of B4N4-Ⅰ is slightly higher than that of c-BN.
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