Abstract Dusty olivine containing Fe‐rich kamacite grains in chondrules can faithfully record the early solar magnetic fields. To retrieve paleointensity estimates, most experimental protocols are based on the dominance of uniformly magnetized single‐domain (SD) particles. However, direct observation shows that most particles adopt a non‐uniform magnetic structure. This inconsistency potentially represents a major impediment in reliably reconstructing ancient magnetic fields. Here we present a micromagnetic based model, the State Group Algorithm, that enables efficient simulations of thermoremanence acquisition in magnetic particles with single‐vortex (SV) domain states. Our results show that these particles can acquire a thermoremanence that is linear proportional to the external field up to . They also have cooling rate effects that are generally weaker than those of SD particles. Notably, a small subset of SV particles can exhibit negative cooling rate effects, leading to underestimates in paleointensity. We conclude that SV particles are reliable paleomagnetic recorders.
Chen et al. (Fri,) studied this question.