Plastic Deformation and Creep in Solid Helium
Plastic Deformation and Creep in Solid Helium
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固体氦中的塑性变形和蠕变
DOI：
10.1007/s10909-019-02231-5
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发表时间：
2019
影响因子：
2
通讯作者：
J. Beamish
中科院分区：
文献类型：
--
作者：
J. Beamish
氦晶体是量子固体，具有不同寻常的机械性能。量子零点运动防止氦冻结，除非施加压力，而且氦晶体非常可压缩，弹性常数比传统固体的弹性常数小几个数量级。在这种量子固体中，隧穿允许原子交换，缺陷在低温下很容易移动。在四种晶体中，位错和同位素杂质的异常迁移率[12pt]{minimum}\usepackage{amsath}\usepackage{wa ysym}\usepackage{amsfonts}\usepackage{amsbsy}\usepackage{mathsfs}\usepackage{upgreek}\setlong{\oddsidemargin}{-69pt}\Begin{Document}$^4$\end{Document}He晶体在小应变下可使其剪切弹性模数降低90%。对于大应变，固体氦晶体在熔点附近非常柔软和延展，在毫巴应力下流动。在低应变率下，这种高温蠕变是热激活的，涉及空位的扩散，这允许位错通过攀升移动。在低温下，这些过程被冻结，氦晶体的延展性要差得多。变形是通过突然滑移事件--位错雪崩--进行的，其大小和时间范围很大。在这篇论文中，我们回顾了Solid中的塑性变形和流动的实验。4\Documentclass[12pt]{Minimum}\usepackage{amsath}\usepackage{wa ysym}\usepackage{amsfonts}\usepackage{amsbsy}\usepackage{mathsfs}\usepackage{upgreek}\setlong{\oddsidemargin}{-69pt}\Begin{Documentclass$$^4$\end{DocumentClass[12pt]{Minimum}\usepackage{amsath}\usepackage{wanysym\usepackage{amsfonts}\usepackage{amssymsb}\usepackage{amsbsy}\usepackage{mathsfs}\usepackage{upgreek}\setlong{\oddsidemargin}{-69pt}\Begin{文档}$$^3$\end{文档}他在过去50年中，并讨论了从这些实验中确定的固体氦的塑性变形机制。
Helium crystals are quantum solids, with unusual mechanical properties. Quantum zero point motion prevents helium from freezing, unless pressure is applied, and helium crystals are extremely compressible, with elastic constants orders of magnitude smaller than those of conventional solids. In such quantum solids, tunneling allows atomic exchange and defects may move easily at low temperatures. The unusual mobility of dislocations and isotopic impurities in 4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^4$$\end{document}He crystals can reduce their shear modulus at small strains by as much as 90%. For large strains, solid helium crystals are extraordinarily soft and ductile near their melting points, flowing under millibar stresses. At low strain rates, this high-temperature creep is thermally activated and involves diffusion of vacancies, which allow dislocations to move via climb. At low temperatures, these processes freeze out and helium crystals are much less ductile. Deformation proceeds via sudden slip events—dislocation avalanches—with a wide range of sizes and timescales. In this paper, we review experiments on plastic deformation and flow in solid 4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^4$$\end{document}He and 3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^3$$\end{document}He during the past 50 years, and discuss the plastic deformation mechanisms in solid helium that have been identified from these experiments.
通过移动导线探测固体 4He 的塑性特性：高应力下的粘弹性和随机行为
影响因子：
2
作者：
Ahlstrom S
通讯作者：
Ahlstrom S