中国物理B ›› 2018, Vol. 27 ›› Issue (3): 36101-036101.doi: 10.1088/1674-1056/27/3/036101
• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇 下一篇
Lun Xiong(熊伦), Jing Liu(刘景)
Lun Xiong(熊伦)1,2,3, Jing Liu(刘景)3
摘要: The structural phase transition, strength, and texture of vanadium have been studied under nonhydrostatic compression up to 70 GPa using an angle-dispersive radial x-ray diffraction technique in a 2-fold paranomic diamond anvil cell and up to 38 GPa using an angle-dispersive x-ray diffraction technique in a modified Mao-Bell diamond anvil cell at room temperature. We have confirmed a phase transition from body-centered cubic structure to rhombohedral structure at 27-32 GPa under nonhydrostatic compression. The radial x-ray diffraction data yields a bulk modulus K0=141(5) GPa and its pressure derivative K'0=5.4(7) for the bcc phase and K0=154(13) GPa with K'0=3.8(3) for the rhombohedral phase at ψ=54.7°. The nonhydrostatic x-ray diffraction data of both bcc and rhombohedral phases yields a bulk modulus K0=188(5) GPa with K'0=2.1(3). Combined with the independent constraints on the high-pressure shear modulus, it is found that the vanadium sample can support a differential stress of ~1.6 GPa when it starts to yield with plastic deformation at ~36 GPa. A maximum differential stress as high as ~1.7 GPa can be supported by vanadium at the pressure of ~47 GPa. In addition, we have investigated the texture up to 70 GPa using the software package MAUD. It is convinced that the body-centered cubic to rhombohedral phase transition and plastic deformation due to stress under high pressures are responsible for the development of texture.
中图分类号: (X-ray diffraction)