Wang Pei, Kumar Ravhi, Sankaran Esakki Muthu, Qi Xintong, Zhang Xinyu, Popov Dmitry, Cornelius Andrew L, Li Baosheng, Zhao Yusheng, Wang Liping
High Pressure Science and Engineering Center, University of Nevada, Las Vegas , Las Vegas, Nevada 89154, United States.
Department of Geosciences, Stony Brook University , Stony Brook, New York 11794, United States.
Inorg Chem. 2018 Feb 5;57(3):1096-1105. doi: 10.1021/acs.inorgchem.7b02550. Epub 2018 Jan 23.
Vanadium diboride (VB) with an AlB-type structure has been synthesized at 8 GPa and 1700 K in a D-DIA-type multianvil apparatus. The obtained bulk modulus is B = 262(2) GPa with fixed B' = 4.0 for VB via high-pressure X-ray diffraction measurements. Meanwhile, VB has also been demonstrated to possess a high Vickers hardness of 27.2 ± 1.5 GPa, a high thermal stability of 1410 K in air, among the highest for transition-metal borides, and an extremely low resistivity value (41 μΩ cm) at room temperature. Results from first-principles calculations regarding the mechanical and electronic properties of VB are largely consistent with the experimental observations and further suggest that VB possesses simultaneously the properties of a hard and refractory ceramic and those of an excellent electric conductor.
具有AlB型结构的二硼化钒（VB）已在D-DIA型多砧装置中于8吉帕斯卡和1700开尔文的条件下合成。通过高压X射线衍射测量，对于VB，在固定B' = 4.0的情况下，获得的体模量为B = 262(2)吉帕斯卡。同时，VB还被证明具有27.2±1.5吉帕斯卡的高维氏硬度、在空气中1410 K的高热稳定性（在过渡金属硼化物中是最高的之一）以及室温下极低的电阻率值（41微欧厘米）。关于VB力学和电子性质的第一性原理计算结果与实验观察结果基本一致，并进一步表明VB同时具有硬质难熔陶瓷和优良导电体的性质。
