Systematics of the post-spinel tranisition in Fe-bearing compositions

含铁组合物中尖晶石后转变的系统学

• 批准号: 24942365
• 负责人: Professor Dr. Daniel J. Frost
• 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: Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/24942365?language=en
• 关键词: Systematics; post; spinel; tranisition; Fe

Phases with the spinel structure occur in many fundamental chemical systems of geological importance and a number of these are known to undergo one or more phase transformations at transition zone and lower mantle pressures. The transformation mechanisms and crystal chemical factors controlling the formation of particular postspinel structures are poorly understood, as are the P-T stabilities of the post-spinel phases. Our goal is to address this knowledge deficit through a study combining in situ experiments (DAC and multi-anvil) at high P and T (10-25 GPa and up to 1600°C), with TEM characterisation (microstructures) and atomistic computer simulations. We will concentrate on relevant Fe-bearing systems: Fe3O4 (magnetite), Fe3O4-FeCr2O4 (magnetite-chromite) and FeAl2O4 (hercynite). Different theoretical approaches will be tested by comparison with experimental data. We seek to develop thermodynamic descriptions of the transformations, as well as understanding their mechanisms (by TEM). The resulting thermodynamic data will be used to calculate phase relations in these fundamental systems at high P and T. The implications of these transformations for natural systems will be explored.

具有尖晶石结构的相出现在许多具有地质重要性的基本化学系统中，并且已知其中许多在过渡带和较低地幔压力下经历一次或多次相变。人们对控制特定后尖晶石结构形成的转变机制和晶体化学因素知之甚少，后尖晶石相的 P-T 稳定性也是如此。我们的目标是通过将高 P 和 T（10-25 GPa 和高达 1600°C）下的原位实验（DAC 和多砧）与 TEM 表征（微观结构）和原子计算机模拟相结合的研究来解决这一知识缺陷。我们将专注于相关的含铁体系：Fe3O4（磁铁矿）、Fe3O4-FeCr2O4（磁铁矿-铬铁矿）和 FeAl2O4（铁铝矿）。将通过与实验数据的比较来测试不同的理论方法。我们寻求对这些转变进行热力学描述，并了解它们的机制（通过 TEM）。由此产生的热力学数据将用于计算这些基本系统在高 P 和 T 下的相关系。将探讨这些转换对自然系统的影响。

项目成果

Detecting the spinel–post-spinel transition in Fe3O4 by in situ electrical resistivity measurements

• DOI: 10.1080/08957950903392092
• 发表时间: 2009-12
• 期刊: High Pressure Research
• 影响因子: 2
• 作者: K. Schollenbruch;A. Woodland;D. Frost;F. Langenhorst

The stability of hercynite at high pressures and temperatures

铁铝尖晶石在高压和高温下的稳定性

• DOI: 10.1007/s00269-009-0317-z
• 发表时间: 2009
• 期刊: Physics and Chemistry of Minerals
• 影响因子: 1.4
• 作者: Schollenbruch;Woodland AB;Frost DJ
• 通讯作者: Frost DJ

In situ determination of the spinel–post-spinel transition in Fe3O4 at high pressure and temperature by synchrotron X-ray diffraction

同步加速器X射线衍射原位测定高压高温下Fe3O4中的尖晶石-后尖晶石转变

• DOI: 10.2138/am.2011.3642
• 发表时间: 2011
• 期刊: American Mineralogist
• 影响因子: 3.1
• 作者: Schollenbruch K;Woodland AB;Frost DJ ;Wang Y;Sanehira T;Langenhorst
• 通讯作者: Langenhorst