Development of simultaneous measurements system of electric conductivity and x-ray diffraction on mantle minerals at high pressure and temperature
Development of simultaneous measurements system of electric conductivity and x-ray diffraction on mantle minerals at high pressure and temperature
批准号:
15340187
负责人:
NAGAI Takaya
金额:
$9.98万
依托单位:
依托单位国家:
日本
项目类别:
Grant-in-Aid for Scientific Research (B)
财政年份:
2003
资助国家:
日本
项目状态:
已结题
起止时间:
2003 至 2004
中文摘要
本研究项目设计了一种可同时用于电阻测量和X射线衍射测量的金刚石压腔。DAC基本改装为杠杆弹簧式DAC,安装了测量电阻的双电极模型。用FZ法合成了一系列磁铁矿(Fe_3O_4)-硫尖晶石(Fe_2TiO_4)固溶体单晶。然后对这些样品进行了电阻测量,同时进行了X射线衍射仪的测量,所有样品的电阻都随着压力的增加而逐渐减小,这可能是由于电子跃迁和能带重叠机制所致。然而,在某些临界压力之上,电阻突然显示出不依赖于压力。Fe_2TiO_4和Fe_3O_4固溶体的临界压力随固溶体中铁含量的增加而增加,如Fe_2TiO_4的临界压力约为6.5 Gpa,Fe_3O_4的临界压力约为24 Gpa。有证据表明,在临界压力下会发生结构性转变。根据Fe2TiO4高压下的单晶结构分析实验,结构转变可以归结为从立方对称到四方对称的转变,Mn3O4型结构可以被认为是Fe2TiO4高压形式的候选者。本研究项目中新设计的体系可以提供一些关于晶体结构与电阻关系的有趣和重要的信息。
英文摘要
A diamond anvil cell, which can apply to electric resistance and x-ray diffraction measurements simultaneously, was designed in this research project. The DAC is basically modified the lever & spring type DAC and two electrodes model for electric resistance measurements is installed the DAC.A series of single crystals of the magnetite (Fe_3O_4)-ulvospinel (Fe_2TiO_4) solid solution were synthesized by the FZ method. Then, electric resistance measurements were performed on those samples and x-ray diffraction measurements were also performed at the same time.Electric resistances on all samples decrease gradually with increasing pressure probably due to the electron hopping and the band overlapping mechanism. However, the electric resistances suddenly show no pressure-dependency-above some critical pressures. The critical pressure increases with iron content in the solid solution of Fe_<3-x>Ti_xO_4. For example, the critical pressures are about 6.5GPa for Fe_2TiO_4 and about 24GPa for Fe_3O_4. X-ray powder diffraction patterns obtained above the critical pressure showed that some single diffraction peaks split into doublet peaks above the critical pressure. The evidence suggests a structural transition occurs at the critical pressure. According to the single crystal structure analysis experiments on Fe_2TiO_4 at high pressure, the structural transition could be assigned as the transition from cubic to tetragonal symmetry and the Mn_3O_4 type structure can be proposed as a candidate of the high-pressure form of Fe_2TiO_4. The newly designed system in this research project can provide some interesting and important information about the relationship between the crystal structures and electric resistances.
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DOI:
10.2138/am-2003-1005
发表时间:
2003-10
期刊:
American Mineralogist
影响因子:
3.1
作者:
[T. Nagai;H. Kagi;T. Yamanaka]
通讯作者:
T. Nagai;H. Kagi;T. Yamanaka
Variation of hydrogen bonded O【triple bond】O distances in goethite at high pressure
针铁矿高压下氢键O【三键】O距离的变化
DOI:
--
发表时间:
2003
期刊:
American Mineralogist 88
影响因子:
--
作者:
[W.Nakagawara et al., Takaya Nagai]
通讯作者:
Takaya Nagai
中性子と高圧のカップリングでなにが見えるか?
当中子和高压耦合时你能看到什么?
DOI:
--
发表时间:
2004
期刊:
高圧力の科学と技術 14
影响因子:
--
作者:
[M.Sugiyama, M.Annaka, K.Hara, M.E.Vigild, G.E.Wignall, 永井隆哉]
通讯作者:
永井隆哉
DOI:
--
发表时间:
2004
期刊:
Japanese Magazine of Mineralogical and Petrological Sciences 33
影响因子:
--
作者:
[M.Annaka, M.Sugiyama, M.Kasai, T.Nakahira, T.Matsuura, H.Seki, T.Aoyagi, T.Okano, M.Miyazaki et al., Takaya Nagai]
通讯作者:
Takaya Nagai
中性子散乱実験と鉱物学の新展開
中子散射实验和矿物学新进展
DOI:
--
发表时间:
2004
期刊:
岩石鉱物科学 33
影响因子:
--
作者:
[T.Matsuura, M.Sugiyama, M.Annaka, Y.Hara, T.Okano, 永井隆哉]
通讯作者:
永井隆哉
共 13 条
Origin of diamonds derived from the Earth's lower mantle
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批准号:18340167
-
项目类别:Grant-in-Aid for Scientific Research (B)
-
资助金额:$10.9万
-
财政年份:2006
-
负责人:NAGAI Takaya
-
依托单位:
Crystal structure refinement of mantle minerals under high pressure and temperature using Rietveld method
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批准号:13440162
-
项目类别:Grant-in-Aid for Scientific Research (B)
-
资助金额:$9.22万
-
财政年份:2001
-
负责人:NAGAI Takaya
-
依托单位:
Effective factors in the kinetics of pressure-induced transformation.
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批准号:10640463
-
项目类别:Grant-in-Aid for Scientific Research (C)
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资助金额:$2.11万
-
财政年份:1998
-
负责人:NAGAI Takaya
-
依托单位:
海外基金