权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

The study of the materials of the lower mantle by a laser heated diamond anvil cell and analytical electron microscopy

用激光加热金刚石砧室和分析电子显微镜研究下地幔的材料

基本信息

批准号：
12304030
负责人：
FUJINO Kiyoshi
金额：
$ 28.56万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

In this study, the YLF laser-heated diamond anvil cell (DAC) experiments at up to 100 GPa and 3000 K and analytical transmission electron microscopy (ATEM) using the ultrathin foils prepared by ultramicrotomy were developed. By the combined method of a laser-heated DAC, synchrotron X-ray diffraction and ATEM, the following results were obtained.1) High pressure syntheses of CaMgSi_2O_6-CaFeSi_2O_6 pyroxene at 30-80 Gpa and 1700-2200 K and analyses of the samples revealed that the Ca solubility in MgSiO_3 perovskite was about 1-2 mole % at 30 Gpa in the CaMgSi_2O_6 end and does not seem to change with increasing the Fe content or pressure, while the Mg solubility in CaSiO_3 perovskite was about 4 mole % at 30 Gpa in the CaMgSi_2O_6 end but the (Mg,Fe) solubility in CaSiO_3 perovskite significantly increased up to 20-30 mole % with increasing the Fe content and pressure.2) High pressure syntheses of (Mg,Fe)SiO_3-Al_2O_3 gel at 30-60 GPa and 1800-2000 K and analyses of the samples showed that the Fe solubility in (Mg,Fe)SiO_3 perovskite increased with increasing the Al content in perovskite, indicating the formation of the endmember Fe^<3+>Al^<3+>O_3 in perovskite.3) High pressure syntheses of CaSiO_3-CaTiO_3 glass at 30 Gpa and 1800 K and analyses of the samples showed that the Ti substitution for Si in CaSiO_3 perovakite produced doubling of a unit cell axis, resulting in a double perovskite-like structure in the intermediate composition of this system. This structure is face-centered cubic at high pressure and high temperature, but it inverts to a lower symmetry structure during cooling.

在这项研究中，YLF激光加热金刚石压砧（DAC）实验在高达100 GPa和3000 K和分析透射电子显微镜（ATEM）使用超薄切片制备的金刚石薄膜的发展。通过激光加热DAC、同步辐射X射线衍射和ATEM相结合的方法，1）在30-80 GPa和1700-2200 K下高压合成了CaMgSi_2O_6-CaFeSi_2O_6辉石，并对样品进行了分析。结果表明，在30 GPa下，Ca在MgSiO_3钙钛矿中的溶解度约为1- 2mol%。在30 Gpa下，CaMgSi_2O_6端的Mg在CaSiO_3钙钛矿中的溶解度约为4 mol %，而（Mg，Fe）在CaSiO_3钙钛矿中的溶解度随Fe含量和压力的增加而显著增加，最高可达20-30 mol %。Fe）SiO_3-Al_2O_3体系在30-60 GPa和1800-2000 K下的凝胶化过程，并对样品进行了分析，结果表明，Fe在（Mg，Fe）SiO_3钙钛矿中的溶解度随钙钛矿中Al含量的增加而增加，3）高压合成CaSiO_3-CaTiO_2体系在30 Gpa和1800 K下对CaSiO_3玻璃进行了热处理，并对样品进行了分析。结果表明，Ti取代CaSiO_3钙钛矿中的Si，使其晶胞轴加倍，从而在该系统的中间成分中形成了双钙钛矿结构。该结构在高温高压下为面心立方结构，但在冷却过程中转变为对称性较低的结构。