Effective decoupling of ferromagnetic sublattices by frustration in Heusler alloys

TL;DR

This paper demonstrates that magnetic frustration can be engineered in Ni-Mn-(In, Sn) Heusler alloys, leading to decoupled ferromagnetic sublattices with distinct ordering behaviors, revealing new possibilities for magnetic material design.

Contribution

It introduces a method to achieve highly frustrated ferromagnetic phases in multi-sublattice Heusler alloys through precise tuning of magnetic interactions.

Findings

One sublattice orders ferromagnetically below TC.

The second sublattice remains disordered until a lower temperature.

Fine tuning of interactions enables novel magnetic states.

Abstract

Magnetic frustration in ferromagnetic metallic systems is unusual due to the long-range and symmetric nature of the exchange interactions. In this work we prove that it is possible to obtain a highly frustrated ferromagnetic phase in a multi-sublattices cubic structure through a fine tuning of the magnetic interactions. This peculiar state is achieved in Ni-Mn-(In, Sn) Heusler alloys and results in the effective decoupling of their two intertwined ferromagnetic sublattices. One sublattice is ferromagnetic long range ordered below the macroscopic Curie temperature (TC ) whereas the second one remains disordered until a crossover to a polarized state occurs at T << TC . This result points out that a fine engineering of the magnetic interactions in metallic systems can lead to interesting novel and emergent phenomena.