The equation of state of forsterite to 17.2 GPa and effects of pressure media

Other| February 01, 1996 The equation of state of forsterite to 17.2 GPa and effects of pressure media Robert T. Downs; Robert T. Downs Carnegie Institution of Washington, Geophysical Laboratory and High Pressure Research, Washington, DC, United States Search for other works by this author on: GSW Google Scholar Chang-Sheng Zha; Chang-Sheng Zha Search for other works by this author on: GSW Google Scholar Thomas S. Duffy; Thomas S. Duffy Search for other works by this author on: GSW Google Scholar Larry W. Finger Larry W. Finger Search for other works by this author on: GSW Google Scholar American Mineralogist (1996) 81 (1-2): 51–55. https://doi.org/10.2138/am-1996-1-207 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 Robert T. Downs, Chang-Sheng Zha, Thomas S. Duffy, Larry W. Finger; The equation of state of forsterite to 17.2 GPa and effects of pressure media. American Mineralogist 1996;; 81 (1-2): 51–55. doi: https://doi.org/10.2138/am-1996-1-207 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 Pressure-volume X-ray diffraction data were collected at eight pressures to 17.2 GPa for synthetic single-crystal forsterite, Mg2SiO4. Birch-Murnaghan equation-of-state parameters were determined to be K0 = 125(2) GPa and K′0 = 4.0(4). To ensure hydrostatic conditions, we monitored the diffraction-peak shapes while the sample was in different pressure media: 4:1 methanol-ethanol, He, and Ar. The diffraction peaks for forsterite in 4:1 methanol-ethanol at 12.2 GPa were broadened to such an extent that we believe that any data collected at similar pressures and in this medium may be suspect and should be examined critically. The diffraction-peak profiles for the sample in He were sharp and well-formed, suggesting He provides an excellent medium at pressures ≤17.2 GPa. However, upon decompression, the diffraction peaks of the sample in He also showed significant broadening. This broadening suggests that with increasing pressure He diffused into the crystal, but with the release of pressure the He was unable to diffuse out quickly. The diffraction peaks regained their sharpness after several months. 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.