Dislocation recovery experiment of hydrous olivine as a function of water content and crystallographic orientation

水合橄榄石的位错恢复实验作为含水量和晶体取向的函数

• 批准号: 229061489
• 负责人: Professor Dr. Tomoo Katsura
• 金额: --
• 依托单位: Bayerisches Forschungsinstitut für Experimentelle Geochemie und Geophysik (BGI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/229061489?language=en
• 关键词: Dislocation; recovery; experiment; hydrous; olivine

Deformation experiments suggested that dislocation mobility should be enhanced by water incorporation, and the water-content dependence of dislocation mobility in the [100](010) (Type-A), [100](001) (Type-E) and [001](100) (Type-C)slips should be higher in this order. The overall water-content exponent of dislocation mobility should be 1.2. In order to examine these results, the applicant conducted dislocation recovery experiment in the preceding project and obtained the following results. (1) In spite of at least four reported fabric types (Type A, B, C and E), there are only two kinds of dislocations. Dislocations for Type A and E fabrics are edge dislocations with a [100] Burgers vector (a-dislocations), whereas those for Type B and C fabrics are screw dislocations with a [001] Burgers vector (c-dislocations).(2) The activation energies and volumes of annihilation-rate constants of a- and c-dislocations are identical, and are also comparable with those of the Si diffusions. These facts suggest that motions of these two dislocations are diffusion-controlled. (3) The water-content exponents of annihilation-rate constants of a- and c-dislocations are 0.2±0.4 and -0.5±0.2, respectively. Namely, their water content dependences are zero with in uncertainty and negative, respectively.Although these striking results were thus obtained, there are insufficient Points.(1) Uncertainties of the annihilation-rate constants of a-dislocations by the [100](010) slip are very large.(2) Data points of the annihilation-rate constants of c-dislocations by the [001](010) slip are too few.(3) It is not clear whether dislocations accounting for Type-E fabric are really absent under any condition.(4) It is not clear whether c-dislocations responsible for Type-B and Type-C fabrics are identical or not. For these reasons, the following experiments will be conducted in this project.(1) Data points of water-content dependence of annihilation-rate constants of a-dislocations will be reinvestigated by means of more precise techniques.(2) More data points will be produced for water-content dependence of annihilation-rate constants of c-dislocations.(3) Olivine single crystals will be sheared in the [100] direction on the (001) plane under various pressure, temperature, strain-rate and water-content conditions to examine their dislocation textures.(4) Pressure and temperature dependence of c-dislocations by the [001](100) slip and water-content dependence of those by the [001](010) slip will be obtained.

变形实验表明，水的掺入会增强位错的活动性，且[100]（010）（A型）、[100]（001）（E型）和[001]（100）（C型）滑移中位错活动性的含水量依赖性依次较高。位错迁移率的总含水率指数应为1.2。为了检验这些结果，申请人在前述项目中进行了位错恢复实验，并获得了以下结果。(1)尽管至少有四种组构类型（A型、B型、C型和E型），但只有两种位错。A型和E型组构的位错是具有[100] Burgers矢量的刃位错（a-位错），而B型和C型组构的位错是具有[001] Burgers矢量的螺旋位错（c-位错）。(2)的激活能和体积的湮灭速率常数的a-和c-位错是相同的，也是可比的Si扩散。这些事实表明，这两个位错的运动是扩散控制。(3)α位错和c位错的湮没速率常数的含水指数分别为0.2±0.4和-0.5 ~0.2。也就是说，它们对含水量的依赖性分别为零和负。虽然这样得到了这些惊人的结果，但还有不足之处。(1)[100]（010）滑移对α位错的湮灭速率常数的影响很大。(2)[001]（010）滑移引起的c位错湮灭速率常数的数据点太少。(3)目前尚不清楚是否位错占E型组构真的不存在在任何条件下。(4)目前尚不清楚造成B型和C型组构的C型位错是否相同。基于这些原因，本项目将进行以下实验。(1)将通过更精确的技术重新研究α位错的湮灭速率常数与水含量相关的数据点。(2)将产生更多的数据点的水含量的c-位错的湮灭速率常数的依赖性。(3)在不同的压力、温度、应变速率和含水量条件下，对橄榄石单晶在（001）面上进行[100]方向的剪切，以研究其位错织构。(4)得到了[001]（100）滑移引起的c位错的压力和温度依赖性以及[001]（010）滑移引起的c位错的水含量依赖性。

项目成果

Temperature dependence of [100](010) and [001](010) dislocation mobility in natural olivine

天然橄榄石中[100](010)和[001](010)位错迁移率的温度依赖性

• DOI: 10.1016/j.epsl.2016.02.029
• 发表时间: 2016
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: S. Blaha;Z. Pintér;R. Farla;T. Kawazoe;N. Miyajima;K. Michibayashi;T. Katsura
• 通讯作者: T. Katsura