Chemistry dependence of the grain boundary character distribution (GBCD) of olivine

橄榄石晶界特征分布 (GBCD) 的化学依赖性

• 批准号: 321722160
• 负责人: Dr. Marcel Thielmann, Ph.D., since 12/2018
• 金额: --
• 依托单位: Department of Materials
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/321722160?language=en
• 关键词: Chemistry; dependence; grain; boundary; character

The grain boundary character distribution (GBCD) is a measure of the natural frequency of different grain boundaries; it is anisotropic and scale invariant for polycrystals without crystal preferred orientations. Based on these observations it was concluded that the GBCD is an intrinsic parameter related to the crystal structure. The GBCD gives the full 5 parameters needed to describe the geometry of a grain boundary, related to the grain boundary energy. Properties of polycrystalline materials are strongly influenced by the network of their internal interfaces. This is because the properties of grain boundaries differ significantly from those of the ideal crystal lattice. For example, incompatible elements can be stored (segregated) on the grain boundary planes and element diffusion is orders of magnitude faster along grain boundaries than through the crystal lattice.Various studies show that the GBCD changes with chemistry of the grain boundaries and modifications are readily observed at concentrations below one wt.%. These chemical impurities also influence the grain boundary energy, grain boundary mobility and its strengths.Preliminary measurements on olivine aggregates also show a chemical dependence of the GBCD. Based on these promising preliminary results, I propose to investigate the effect of chemical variation (including the presence of melt) on the GBCD of olivine. Such data are urgently needed to quantify grain boundary controlled processes in olivine dominated rocks, they may, for example, explain the large discrepancies in deformation experiments that seem to correlate with the materials purity.With the planned research the following questions will be addressed: (iv) Do grain boundary plane frequencies depend on the chemical environment?a. Do grain boundary frequencies vary with the addition of relatively incompatible elements to the aggregate?b. Do grain boundary frequencies change in the presence of melt?(v) Which are the important grain boundaries to be studied in depth? (vi) Do changes in the GBCD affect the activation of different deformation mechanisms, such as deformation in the diffusional accommodated grain boundary sliding regime?

晶界特征分布（GBCD）是不同晶界固有频率的量度；对于没有晶体择优取向的多晶来说，它是各向异性和尺度不变的。基于这些观察，得出结论：GBCD 是与晶体结构相关的内在参数。 GBCD 提供了描述晶界几何形状所需的全部 5 个参数，这些参数与晶界能量相关。多晶材料的性能受到其内部界面网络的强烈影响。这是因为晶界的性质与理想晶格的性质显着不同。例如，不相容的元素可以存储（隔离）在晶界平面上，元素沿晶界的扩散速度比通过晶格的扩散速度快几个数量级。各种研究表明，GBCD 随晶界化学性质的变化而变化，并且修改很容易在低于 1 wt.% 的浓度下观察到。这些化学杂质也会影响晶界能、晶界迁移率及其强度。对橄榄石聚集体的初步测量也显示出 GBCD 的化学依赖性。基于这些有希望的初步结果，我建议研究化学变化（包括熔体的存在）对橄榄石 GBCD 的影响。迫切需要这些数据来量化橄榄石为主的岩石中的晶界控制过程，例如，它们可以解释似乎与材料纯度相关的变形实验中的巨大差异。通过计划的研究，将解决以下问题：（ iv) 晶界面频率取决于化学环境吗？ 晶界频率是否会随着骨料中相对不相容元素的添加而变化？b． 存在熔体时晶界频率会发生变化吗？(v) 哪些是需要深入研究的重要晶界？ (vi) GBCD 的变化是否会影响不同变形机制的激活，例如扩散适应晶界滑动机制中的变形？

项目成果

Weathering of Bi-bearing tennantite

含铋铁矿的风化

• DOI: 10.1016/j.chemgeo.2018.07.032
• 发表时间: 2018
• 期刊: Chemical Geology
• 影响因子: 3.9
• 作者: Keim M. F;Staude S;Marquardt K;Bachmann K;Opitz J;Markl G.
• 通讯作者: Markl G.

Grain boundary diffusion and its relation to segregation of multiple elements in yttrium aluminum garnet

钇铝石榴石晶界扩散及其与多种元素偏析的关系

• DOI: 10.5194/ejm-32-675-2020
• 发表时间: 2021
• 作者: Polednia;Dohmen;Marquardt
• 通讯作者: Marquardt

A transmission x-ray microscopy and NEXAFS approach for studying corroded silicate glasses at the nanometre scale

• DOI: 10.13036/17533562.59.1.043
• 发表时间: 2018-02
• 期刊: Physics and Chemistry of Glasses-european Journal of Glass Science and Technology Part B
• 影响因子: 0.6
• 作者: M. Kutzschbach;P. Guttmann;K. Marquardt;S. Werner;K. Henzler;M. Wilke;Deutsches GeoForschungsZentrum Potsdam;Helmholtz-Zentrum Berlin fur Materialien und Energie-Helmholtz-Zentrum-Berlin-fur-Materialien-und-1667842994

Evidence for complex iron oxides in the deep mantle from FeNi(Cu) inclusions in superdeep diamond

• DOI: 10.1073/pnas.2004269117
• 发表时间: 2020-09-01
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Anzolini, Chiara;Marquardt, Katharina;Nestola, Fabrizio
• 通讯作者: Nestola, Fabrizio

Role of inclination dependence of grain boundary energy on the microstructure evolution during grain growth

• DOI: 10.1016/j.actamat.2020.02.043
• 发表时间: 2020-04
• 期刊: Acta Materialia
• 影响因子: 9.4
• 作者: Hesham Salama;J. Kundin;O. Shchyglo;V. Mohles;K. Marquardt;I. Steinbach