About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
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Symposium
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Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
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Presentation Title |
E-4: Grain Boundary Energy Variation Related to the GBPD in Forsterite, Mg2SiO4, as a Function of Grain Size |
Author(s) |
Alexandra Austin, Marina Sedlak, Louise Rossett, Sanae Koizumi, Katharina Tinka Marquardt |
On-Site Speaker (Planned) |
Katharina Tinka Marquardt |
Abstract Scope |
Forsterite is not only of interest for its high melting point (1890 °C), low thermal expansion, low dielectric permittivity (~70×10-12 F/m at 1 MHz), and excellent insulating properties at high temperatures but also as the dominating mineral in Earth’s upper mantle.
We present measurements of the relative grain boundary energy for average grain sizes of 0.2, 3.8, 5.3, 9.4 µm and corresponding grain boundary plane distributions (GBPD). We use grain boundary groove profiles obtained from atomic force microscopy of thermally etched samples to extract the grain boundary energy anisotropy spread. The groove geometry was evaluated using a simplified form of Young's equation, approximating the surface energy as constant and neglecting the torque terms. The GBPD was obtained by measuring ~230.000 grain boundary segments from electron backscatter diffraction data. We will discuss the observed relative grain boundary energy variation and plane populations observed for these samples of different grain sizes. |