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Title: Development of High-Pressure Multigrain X-Ray Diffraction for Exploring the Earth’s Interior

Journal Article · · Engineering
 [1];  [1];  [2];  [3]
  1. Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai (China)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
  3. Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai (China); Carnegie Inst. of Washington, Washington, D.C. (United States)

The lower mantle comprises >55% by volume of our planet and enigmatic seismic features in the deep lower mantle call for interperations from high pressure-temperature (P-T) petrological experiments. Studying phase changes in a realistic bulk composition or with addition of volatiles requires in situ phase identification and structure analysis in a multiphase assemblage under corresponding high P-T conditions. In a powder X-ray diffraction (XRD) pattern, however, peaks of new structures and minor phases are often overshadowed by the diffraction of coexisting major phases. In the past 5 years, we have overcome the difficulties and successfully studied new structures and minor phases in great detail in situ under deep lower manlte conditions applying the multigrain XRD technique that treats each individual 100-500 nm-size grains as a single-crystal in a sample consisting of multiple phases and multiple crystals. This paper summarized the advantages of the multigrain XRD technique and provided an example of identification of hydrous phases with average ~100 nm grain size in a multiphase assemblage through combination of in situ phase identification and ex situ microscopic analysis.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
National Natural Science Foundation of China (NSFC); USDOE National Nuclear Security Administration (NNSA); National Science Foundation (NSF); USDOE Office of Science (SC)
Grant/Contract Number:
AC02-06CH11357
OSTI ID:
1566152
Journal Information:
Engineering, Vol. 5, Issue 3; ISSN 2095-8099
Publisher:
Engineering Sciences PressCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 12 works
Citation information provided by
Web of Science

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