Multilevel model for magnetic deflagration in nanomagnet crystals

TL;DR

This paper develops a comprehensive multilevel theoretical model for magnetic deflagration in nanomagnet crystals, accounting for all energy levels, and demonstrates improved agreement with experimental data, especially under strong transverse magnetic fields.

Contribution

It introduces a multilevel model that includes all energy levels for magnetic deflagration, enhancing accuracy in predicting deflagration velocity and temperature.

Findings

All energy levels significantly affect deflagration parameters.

Strong transverse magnetic fields alter spin-state structures and activation energies.

Predicted front velocity aligns better with experimental results for Mn12-acetate.

Abstract

We extend the existing theoretical model for determining the characteristic features of magnetic deflagration in nanomagnet crystals. For the first time, all energy levels are accounted for calculation of the the Zeeman energy, the deflagration velocity, and other parameters. It reduces the final temperature and significantly changes the propagation velocity of the spin-flipping front. We also consider the effect of a strong transverse magnetic field, and show that the latter significantly modifies the spin-state structure, leading to an uncertainty concerning the activation energy of the spin flipping. Our front velocity prediction for a crystal of Mn$_{12}$-acetate in a longitudinal magnetic field is in much better agreement with experimental data than the previous reduced-model results.