2018/03/05 by Li Zhang, Hongsheng Yuan, Yue Meng +1 · 1 citation
Earth and Planetary Sciences · Materials Science · Physics and Astronomy · Chemistry · #High-pressure geophysics and materials #Crystal Structures and Properties #Advanced Condensed Matter Physics #Crystallite #Mantle (geology) #Phase (matter) #Hexagonal crystal system #Diffraction #Hexagonal phase #Materials science #Geology #Mineralogy #Crystallography #Chemistry #Chemical engineering #Geochemistry #Optics #Physics
paper · pdf · doi:10.1073/pnas.1720510115
openalex publication_date 2018/03/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Significance The lower mantle is potentially the most massive water reservoir in our planet, which largely depends on availability of hydrous minerals which can store and transport water down to the deep lower mantle. Experimentally, it is a great challenge to identify an unknown hydrous phase in a multiphase system under high-pressure–temperature conditions corresponding to the deep Earth. We combined powder X-ray diffraction and multigrain indexation to discover a hexagonal hydrous phase in (Fe,Al)OOH at 107–136 GPa and 2,400 K. Tens of individual crystallites, each with its unique orientation matrix, confirm the existence of the hexagonal phase. This study highlights a candidate for water storage.