The 10th Special CMSM-ERATO Joint Seminar 
(The 280th Special CMSM seminar)
Thermoelectric transport in Bi2Se3-Fe3O4 nanocomposites
Dr. Nicolás Pérez
Institute for Metallic Materials,
Leibniz Institute for Solid State and Materials Research, Dresden, Germany
Date & Time: 15:00 - 16:00, June 13th (Fri), 2025.
Place: 5F conference room, Advanced Structural Materials Buiding, Sengen.
Abstract:
In this talk I will present the increase of the thermoelectric figure of merit from 0.14 in Bi2Se3 to 0.21 in Bi2Se3 with added 5 % volume of Fe3O4. After understanding the effect of crystalline texture and disorder in pristine Bi2Se3 [1] the addition of Fe3O4 secondary phase resulted in nanoscale chemical changes leading to a significant increase in carrier concentration. The nature of the chemical process, revealed by atomic resolution TEM, allowed to avoid the otherwise expected severe decrease of the Seebeck coefficient [2]. In addition, the iron oxide nanoparticles secondary phase effectively reduced the thermal conductivity. Both, the increase of the power factor and the decrease of the thermal conductivity was achieved. Finally the inclusion of the ferrimagnetic Fe3O4 nanoparticles had significant consequences for the magnetoresistance characteristics of the composites, pointing out to a more profound effect on the electronic structure of Bi2Se3 by magnetic proximity effect and controlled nanoscale disorder [3]. Both characteristics reconfigured electronic transport.
A brief overview of the scientific activities in the PPMS Lab of the IFW-Dresden regarding electron and phonon transport in materials relevant for thermoelectricity applications will be presented as well.
References
[1] S. Bayesteh et al. Mat. Today Phys. 24 (2022) 100669
[2] S. Sailler et al. Mat. Today Phys. 46 (2024) 101477
[3] N. Pérez et al. Analen d. Phys. 2025 (submitted)
(Contact)
Ken-ichi Uchida,
Spin Caloritronics Group
E-mail:
UCHIDA.Kenichi[at]nims.go.jp
