Memory effects of domain structures during displacive phase transitions; a high-temperature TEM study of quartz and anorthite

Other| February 01, 1997 Memory effects of domain structures during displacive phase transitions: A high-temperature TEM study of quartz and anorthite Hongwu Xu; Hongwu Xu Princeton University, Department of Geosciences and Princeton Materials Institute, Princeton, NJ, United States Search for other works by this author on: GSW Google Scholar Peter J. Heaney Peter J. Heaney Search for other works by this author on: GSW Google Scholar American Mineralogist (1997) 82 (1-2): 99–108. https://doi.org/10.2138/am-1997-1-212 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 Hongwu Xu, Peter J. Heaney; Memory effects of domain structures during displacive phase transitions: A high-temperature TEM study of quartz and anorthite. American Mineralogist 1997;; 82 (1-2): 99–108. doi: https://doi.org/10.2138/am-1997-1-212 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract Memory effects associated with the Dauphiné twins in α quartz and the c-antiphase domains (c-APDs) in P1 anorthite have been investigated by in situ hot-stage transmission electron microscopy (TEM). In a set of kinetic experiments, specimens were cycled about their transition temperatures, and changes in the Dauphine twin and c-APD positions were analyzed as a function of maximum annealing temperature and annealing time. The results indicate that Dauphiné twins are strongly pinned by extended defects, such as Brazil twin and grain boundaries, dislocations, and surfaces. However, the memory displayed by Dauphine twin boundaries pinned by point defects degrades with higher annealing temperatures and longer annealing times. An Arrhenius analysis of this behavior yielded an average activation energy for point-defect diffusion of 68.6 kJ/mol.In contrast to the Dauphiné twins of quartz, the c-APDs of anorthite did not appear to interact strongly with extended defects, and they exhibited a nearly perfect memory for all annealing times and temperatures tested. This extremely high fidelity is interpreted as evidence that the positions of c-APDs are fixed by localized Al-Si disorder, which remains unchanged when anorthite is heat treated at <1000 °C. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not currently have access to this article.