气候变化领域集成服务门户(CCPortal): Discovery of New-Structured Post-Spinel MgFe2O4: Crystal Structure and High-Pressure Phase Relations

CCPortal

DOI	10.1029/2020GL087490
	Discovery of New-Structured Post-Spinel MgFe2O4: Crystal Structure and High-Pressure Phase Relations
	Ishii T.; Miyajima N.; Sinmyo R.; Kojitani H.; Mori D.; Inaguma Y.; Akaogi M.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:6
英文摘要	Phase relations in MgFe2O4 at 20–27 GPa and 1,000–1,200 °C were investigated, and a novel post-spinel phase of MgFe2O4 (space group, Pnma) was identified. This phase has a Z-shape framework of edge-sharing (Mg,Fe)O6 octahedra, with other Mg and Fe cations randomly occupying one tetrahedral and two octahedral sites in tunnel spaces within the framework. This structure is similar to Nax (Fe,Ti)xTi2-xO4 phase (0.75 ≤ x ≤ 0.9) with (Fe,Ti)O6 Z-shape framework and tricapped-prism sites for Na. Compression data showed ~6% volume reduction at 16–20 GPa. The recovered phase may have transformed during decompression from the Nax (Fe,Ti)xTi2-xO4-type structure due to cations in the tunnel spaces shifting, probably because of cation-size misfit. The novel phase may be found in impact craters and shocked meteorites and may serve as an indicator of shock P-T conditions. Without crystal structure refinement, post-spinel phases are likely to be misidentified due to similar crystallographic features. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Iron compounds; Magnesium compounds; Meteor impacts; Phase transitions; Positive ions; Rietveld analysis; Compression data; Crystal structure refinement; High pressure; High-pressure phase relations; Magnesioferrite; mantle; spinel; Volume reductions; Crystal structure; crystal structure; crystallography; high pressure; inorganic compound; mantle; phase transition
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170538
作者单位	Department of Chemistry, Gakushuin University, Tokyo, Japan; Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany; Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan; Department of Physics, Meiji University, Kawasaki, Japan; Graduate School of Engineering, Mie University, Tsu, Japan
推荐引用方式 GB/T 7714	Ishii T.,Miyajima N.,Sinmyo R.,et al. Discovery of New-Structured Post-Spinel MgFe2O4: Crystal Structure and High-Pressure Phase Relations[J],2020,47(6).
APA	Ishii T..,Miyajima N..,Sinmyo R..,Kojitani H..,Mori D..,...&Akaogi M..(2020).Discovery of New-Structured Post-Spinel MgFe2O4: Crystal Structure and High-Pressure Phase Relations.Geophysical Research Letters,47(6).
MLA	Ishii T.,et al."Discovery of New-Structured Post-Spinel MgFe2O4: Crystal Structure and High-Pressure Phase Relations".Geophysical Research Letters 47.6(2020).