ZHANG Yong-mei1,2， ZHANG Le-ting1, ZHAO Yu-hong1
（1. School of Materials Science and Engineering, North University of China, Taiyuan 030051, China； 2. School of Science, North University of China, Taiyuan 030051, China）
Abstract： The structural stability, elastic and electronic properties under pressure at 0 K for β-Ti have been investigated by performing first-principles calculations. With the increase of pressure, the structure of β-Ti becomes stabler, which is further confirmed by the calculation for density of state (DOS). The phase transition pressure of α→β is about 64.3 GPa, which is consistent with other theoretical predictions (63.7 GPa) and the experimental result (50 GPa). The pressure dependence of elastic constants shows that the low-pressure limit for a mechanically stable β-Ti is about 50 GPa with low Young’s modulus value of about30.01 GPa, which approaches the value of a human bone (30 GPa). In addition, the pressure dependence of bulk modulus B, shear modulus G, Young’s modulus E, Poisson’s ratio σ, aggregate sound velocities, and ductility/brittleness under different pressures were also discussed. B, G and E ascend monotonously with increasing pressure, while σ descends. β-Ti remains ductile by analysis of B/G under considered pressures.
Key words： first-principles; structural stability; elastic property; electronic structure; Ti
CLD number： TB303 Document code： A
Article ID： 1674-8042（2017）02-0162-06 doi： 10.3969/j.issn.1674-8042-2017-02-008
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高压下β-Ti 的结构稳定性、 弹性和电子性能的第一性原理研究
张永梅1,2, 张乐婷1, 赵宇宏1
（1. 中北大学 材料科学与工程学院， 山西 太原 030051； 2. 中北大学 理学院， 山西 太原 030051）
摘要：应用第一性原理的方法， 研究了高压下β-Ti在0 K下的结构稳定性、 弹性和电子性能。 吉布斯自由能和电子态密度的研究表明， 随着压力的增加， β-Ti 的结构趋于稳定。 β→β 的相变压强为 64.3 GPa， 这一计算结果与其它的理论结果 63.7 GPa 和实验结果 50 GPa相吻合。 弹性常数的计算表明， β-Ti 力学稳定的低压极限约为50 GPa， 该压力下的弹性模量约为30.01 GPa， 接近人体骨骼的弹性模量30 GPa。 另外， 讨论了不同压力下β-Ti体积模量B、 剪切模量G、 杨氏模量E、 泊松比β、 声速和韧性/脆性。 随着压力的增加， B, G, E增加， 但是β减小。 B/G 计算表明， β-Ti具有良好的韧性。
关键词：第一性原理； 结构稳定性； 弹性性能； 电子结构； 钛
引用格式：ZHANG Yong-mei， ZHANG Le-ting, ZHAO Yu-hong. Study on structural stability, elastic and electronic properties for β-Ti under pressure based on first principles. Journal of Measurement Science and Instrumentation, 2017, 8(2)： 162-167. ［doi： 10.3969／j.issn.1674-8042.2017-02-008］
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