Strategies for tuning the thermal conductivity of crystals by means of external fields are rare. Here, we predict the existence of large magnetophononic effects in materials that undergo antiferromagnetic (AFM) ↔ ferromagnetic (FM) phase transitions, which allow for the modulation of the lattice heat conductivity, κL, via the application of magnetic fields.
Specifically, by using first-principles methods we predict a large and anomalous κL increase of ≈40% for the metamagnetic phase transition occurring in bulk FeRh near room temperature. The disclosed magnetophononic effects are caused by large anharmonic spin-phonon couplings, namely, significant differences in the phase space of allowed phonon-phonon collision processes taking place in the respective AFM and FM phases.
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Oxides for new-generation electronics
Dynamical tuning of the thermal conductivity via magnetophononic effects
Claudio Cazorla and Riccardo Rurali
Phys. Rev. B 105, 104401 – Published 1 March 2022
DOI: https://doi.org/10.1103/PhysRevB.105.104401
