ABSTRACT

In this study, synchrotron radiation X-ray diffraction is used to study the equation of state of vanadium nitride in a diamond anvil cell at room temperature. Experimental results reveal the high stability of the cubic structure up to 76 GPa pressure. In addition, the bulk modulus of vanadium nitride derived from XRD data is K₀= 328.4(2.8) GPa with K₀′ = 5.86(0.14). Finally, the high pressure compression behavior is investigated to 80 GPa using density functional theory of first-principle calculations, and the obtained bulk elastic modulus is 316 GPa. Vanadium nitride is not magnetic in the whole pressure range and is metallic.

Highlights

• We have investigated the equation of state of VN under high pressure with silicone oil as the pressure transmitting medium to 76 GPa.

• It was found that the face-centred cubic structure of VN maintains the maximum pressure of 76 GPa.

• We have carried out first-principles calculations and obtained the equation of state, band structure, and electronic density of state of VN to 80 GPa.

摘要

在这项研究中，同步辐射 X 射线衍射用于研究室温下金刚石砧座中氮化钒的状态方程。实验结果表明立方结构在压力高达 76 GPa 时仍具有高稳定性。此外，由XRD数据推导出的氮化钒的体积模量为K ₀ = 328.4(2.8) GPa，其中K ₀ ' = 5.86(0.14)。最后，利用第一性原理计算的密度泛函理论研究了高压压缩至80 GPa的行为，得到的体积弹性模量为316 GPa。氮化钒在整个压力范围内都没有磁性，是金属的。

强调

• 我们研究了高压下VN 的状态方程，硅油作为压力传递介质至76 GPa。

• 据发现，VN 的面心立方结构可保持 76 GPa 的最大压力。

• 我们进行了第一性原理计算，得到了VN 到80 GPa 的状态方程、能带结构和电子态密度。