Quantification of plastic deformation in anorthite using micropillar compression
Abstract
Plagioclase is the most abundant mineral group of the crust and will therefore either control or strongly influence crustal rheology. Yet, we still know little about crystal plasticity in plagioclase as brittle deformation dominates under most laboratory conditions. To overcome past challenges in quantifying crystal plastic deformation in plagioclase, we used micropillar compression to quantify the strength of specific slip systems as well as the stresses necessary for mechanical twinning in anorthite. Pillars with diameters of around 1 micrometre were milled from three differently oriented cuts of the same anorthite single crystals using focused-ion beam. Uniaxial deformation of 36 pillars in total was then conducted inside a scanning-electron microscope under either 25, 300, or 800 degrees Celsius. Most pillars were deformed with a constant displacement rate that corresponds to a strain rate of around 0.001 1/s on the pillars. We find that the critical resolved shear stress (CRSS) for mechanical (pericline) twinning lies at around 300 MPa and is, as expected from previous studies on other materials, insensitive to changes in temperature or strain rate. Pillar deformation in crystals oriented to activate slip exhibit a strong decrease in yield stress with increasing temperature. Among the deformation mechanisms active during pillar deformation, twinning is the easiest under the applied conditions, followed by slip on (011)[100] regardless of temperature. Slip on (011)[0-11] or (0-11)[011] is consistently the hardest mechanism to activate in our anorthite pillars.
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BibTeX
@misc{incel2026quantification,
title = {{Quantification of plastic deformation in anorthite using micropillar compression}},
author = {Sarah Incel and Chunhua Tian and Anja Schreiber and Vladimir Roddatis and Sandra Korte-Kerzel},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.10081},
eprint = {2610.10081},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.10081},
}
RIS
TY - UNPB
TI - Quantification of plastic deformation in anorthite using micropillar compression
AU - Sarah Incel
AU - Chunhua Tian
AU - Anja Schreiber
AU - Vladimir Roddatis
AU - Sandra Korte-Kerzel
PY - 2026
DA - 2026/10/07
PB - arXiv
DO - 10.48550/arxiv.2610.10081
UR - https://arxiv.org/abs/2610.10081
AB - Plagioclase is the most abundant mineral group of the crust and will therefore either control or strongly influence crustal rheology. Yet, we still know little about crystal plasticity in plagioclase as brittle deformation dominates under most laboratory conditions. To overcome past challenges in quantifying crystal plastic deformation in plagioclase, we used micropillar compression to quantify the strength of specific slip systems as well as the stresses necessary for mechanical twinning in anorthite. Pillars with diameters of around 1 micrometre were milled from three differently oriented cuts of the same anorthite single crystals using focused-ion beam. Uniaxial deformation of 36 pillars in total was then conducted inside a scanning-electron microscope under either 25, 300, or 800 degrees Celsius. Most pillars were deformed with a constant displacement rate that corresponds to a strain rate of around 0.001 1/s on the pillars. We find that the critical resolved shear stress (CRSS) for mechanical (pericline) twinning lies at around 300 MPa and is, as expected from previous studies on other materials, insensitive to changes in temperature or strain rate. Pillar deformation in crystals oriented to activate slip exhibit a strong decrease in yield stress with increasing temperature. Among the deformation mechanisms active during pillar deformation, twinning is the easiest under the applied conditions, followed by slip on (011)[100] regardless of temperature. Slip on (011)[0-11] or (0-11)[011] is consistently the hardest mechanism to activate in our anorthite pillars.
ER -