High-pressure phase transition in brucite, Mg(OH) 2

Other| April 01, 1995 High-pressure phase transition in brucite, Mg(OH)2 Thomas S. Duffy; Thomas S. Duffy Carnegie Institution of Washington, Geophysical Laboratory, Washington, DC, United States Search for other works by this author on: GSW Google Scholar Charles Meade; Charles Meade Search for other works by this author on: GSW Google Scholar Yingwei Fei; Yingwei Fei Search for other works by this author on: GSW Google Scholar Ho-Kwang Mao; Ho-Kwang Mao Search for other works by this author on: GSW Google Scholar Russell J. Hemley Russell J. Hemley Search for other works by this author on: GSW Google Scholar American Mineralogist (1995) 80 (3-4): 222–230. https://doi.org/10.2138/am-1995-3-403 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Thomas S. Duffy, Charles Meade, Yingwei Fei, Ho-Kwang Mao, Russell J. Hemley; High-pressure phase transition in brucite, Mg(OH)2. American Mineralogist 1995;; 80 (3-4): 222–230. doi: https://doi.org/10.2138/am-1995-3-403 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract Brucite, Mg(OH)2, was investigated by Raman spectroscopy to pressures of 36.6 GPa under nonhydrostatic conditions and to 19.7 GPa under quasi-hydrostatic conditions. Several new Raman lines are first observed at 4 GPa, demonstrating the existence of a high-pressure structural change. One of the new lines grows over a broad pressure interval, and this growth can be explained by a resonant interaction with the Eg translational mode. Raman data are compared with recent infrared spectroscopy, X-ray diffraction, and neutron diffraction studies of brucite. The structural change is likely to involve displacement or disordering of the H atoms, consistent with neutron diffraction results. The Raman-active O-H stretching vibration in brucite decreases with pressure at the rate of ∼7 cm−1/ GPa, larger than the pressure dependence of the infrared-active stretching vibration by more than a factor of ten. The primary differences in the Raman spectra of Mg(OH)2 and Ca(OH)2 are that the O-H vibrational frequencies in Mg(OH)2 vary linearly with pressure, and the O-H stretching vibration band width increases with pressure at a rate that is an order of magnitude lower for Mg(OH)2 than for Ca(OH)2. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.