Ab initio calculations of the phase diagrams of tin and lead under pressures up to a few TPa

Author:

Smirnov N AORCID

Abstract

Abstract The paper studies relative structural stability for various crystal phases of tin and lead from first principles with the full-potential all-electron full-potential all-electron linear muffin-tin orbital method to pressures of a few TPa both at zero temperature and at T > 0. Using data from our calculations we construct phase diagrams for the two metals in the region of very high compressions and obtain their melting curves. For tin at pressures <100 GPa and zero temperature, we did not find the region of stability of the body-centered orthorhombic (bco) phase, as it was earlier observed in experiments by Salamat et al [2013 Phys. Rev. B 88 104104]. Our calculations suggest that one structural transition from the tetragonal to cubic phase, bct → bcc, occurs in perfect Sn crystal at T = 0 K in the pressure range of about 27–32 GPa. But any deviation from perfection may cause an orthorhombic distortion of its tetragonal phase. At pressures above 100 GPa, the bcc → hexagonal close-packed (hcp) transition exists in both metals, and the phase boundary has a domed shape and does not rise in temperature above 2 kK. This behavior of the phase boundary with the increasing temperature is caused by the softer phonon modes of the bcc structure and the smaller contribution of lattice vibrations to the free energy of the crystal compared to the hcp phase. At pressures above 2.5 TPa and T ≲ 1 kK, lead can also undergo another structural transition, hcp → fcc, but at T > 1.5 kK there must exist the more energetically preferable bcc → fcc transition.

Publisher

IOP Publishing

Subject

Condensed Matter Physics,General Materials Science

Cited by 4 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3