Spin fluctuations and Wigner thermal transport in thermoelectric skutterudites

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• Enrico di Lucente, EPFL
• Wednesday 02 November 2022, 14:00-15:00
• TCM Seminar Room (530), Cavendish Laboratory, Department of Physics.

If you have a question about this talk, please contact Dr M. Simoncelli.

Skutterudites are highly promising functional materials due to their peculiar thermoelectric and magnetic properties. We elucidate the complex phenomenology that takes place in these materials both in terms of spin fluctuations and in the crossover from a Peierls-Boltzmann to a Wigner thermal transport regime, where tunneling of phonon wavepackets emerges. We first study the electronic structure using the state-of-the-art DFT +Hubbard theory to uncover multiple self-consistent magnetic and charge disproportionated configurations. While the lowest energy state is antiferromagnetic but metallic, paramagnetic fluctuations captured through a special quasi random structure open a small gap of 61 meV, in good agreement with experiments. Moreover, in going from the parent compound to the related filled skutterudite, a transition from a Peierls-Boltzmann to a Wigner thermal transport regime arises, where, at working temperature of the devices, the tunneling of phonon wavepackets becomes as relevant as the drifting diffusion.

This talk is part of the Lennard-Jones Centre series.

This talk is included in these lists:

• Hanchen DaDaDash
• Lennard-Jones Centre
• TCM Seminar Room (530), Cavendish Laboratory, Department of Physics

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