Institute of Physics, University Duisburg-Essen, Duisburg, Germany.
J Phys Condens Matter. 2011 Nov 2;23(43):435501. doi: 10.1088/0953-8984/23/43/435501. Epub 2011 Oct 13.
The electronic structure and phonon density of B(13)B(2) boron carbide calculated by Calandra et al (2004 Phys. Rev. B 69 224505) defines this compound as metallic, and the authors predict superconductivity with T(C)s up to 36.7 K. Their results are affected by the same deficiencies as former band structure calculations on boron carbides based on hypothetical crystal structures deviating significantly from the real ones. We present optical mid IR/far IR (MIR/FIR) spectra of boron carbide with compositions between B(4.3)C and B(10.37)C, evidencing semiconducting behaviour at least down to 30 K. There is no indication of superconductivity. The spectra yield new information on numerous localized gap states close to the valence band edge.
由 Calandra 等人（2004 年《物理评论 B》69 224505）计算的 B(13)B(2)硼化硼的电子结构和声子密度将该化合物定义为金属，作者预测超导转变温度 T(C)高达 36.7 K。他们的结果与以前基于与真实结构显著偏离的假设晶体结构的硼化物能带结构计算存在同样的缺陷。我们呈现了组成在 B(4.3)C 和 B(10.37)C 之间的硼化硼的光学中红外/远红外（MIR/FIR）光谱，证明了至少在 30 K 以下的半导体行为。没有超导性的迹象。这些光谱提供了关于价带边缘附近许多局部间隙态的新信息。
