Identify the mechanism controlling the calculated slip CRSS

Determine whether the critical resolved shear stresses calculated for slip in anorthite represent the lattice resistance, or Peierls stress, opposing dislocation glide, rather than the stress required for dislocation nucleation at micropillar surfaces and subsequent glide.

Background

The study finds strong temperature dependence of the strengths of anorthite micropillars oriented for slip, but the experiments cannot distinguish conclusively between dislocation nucleation or multiplication and lattice resistance as the controlling process. Because many observed slip bands connect to pillar surfaces, surface-controlled dislocation-source activity may contribute substantially to the measured stresses.

This distinction is essential for interpreting the reported critical resolved shear stresses as intrinsic material properties and for extrapolating micropillar measurements to larger anorthite grains and natural rocks.

References

It is not conclusive yet, whether the calculated CRSS for slip reflect the stresses necessary for dislocation motion to overcome lattice resistance, i.e., Peierls stress, as dislocation nucleation at the pillar surfaces may play a non-negligible role.

— Quantification of plastic deformation in anorthite using micropillar compression  (2610.10081 - Incel et al., 7 Oct 2026) in Section 6, Conclusion