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Jonathan Leiner: Frustrated Magnetism in Mott Insulating V2O3
Begin: 21.04.2021, 14:10
Location: ZOOM Meeting ID: 958 0426 7376

Adam Dubroka: Study of photo-induced insulator-to-metal transition and excited states in LaCoO3 using femtosecond pump-probe ellipsometry
Begin: 22.04.2021, 14:00
Location: Zoom Meeting ID: 967 5516 9898

Dalibor Repček: Magnetoelectric behaviour of EuTiO3 ceramics
Begin: 28.04.2021, 14:10
Location: ZOOM Meeting ID: 958 0426 7376

 
Title: Ernst Bauer: Improved thermoelectric performance of bulk and thin film full-Heusler systems based on Fe2VAl
Number: 2/21
Status: Closing date exceeded
Begin: Wednesday, 20.01. 2021, 14:10
Tutor: Vladimír Sechovský
Location: ZOOM Meeting ID: 958 0426 7376


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We have a pleasure to invite you to attend the joint seminar
of the Department of Condensed Matter Physics (DCMP)
and the Materials Growth and Measurement Laboratory (MGML) http://mgml.eu.

 

Program

 

Improved thermoelectric performance of bulk and thin film full-Heusler systems based on Fe2VAllecture given by:

Ernst Bauer

1)Institute of Solid State Physics, Technische Universität Wien, A-1040 Wien, Austria
2)Christian Doppler Laboratory for Thermoelectricity, Technische Universität Wien, A-1040 Wien, Austria

 

https://cesnet.zoom.us/j/95804267376
Meeting ID: 958 0426 7376 

on Wednesday, 20.1. 2021 from 14:10 CET (13.10 UTC) 

Passcode will be provided on request at  This e-mail address is being protected from spambots. You need JavaScript enabled to view it

 

Vladimír Sechovský
On behalf of the DCMP and MGML


Abstract 

Cubic full-Heusler, X2YZ, and half-Heusler XYZ systems have been proven to be very promising active thermoelectric materials because i) of their thermoelectric performance and ii) because of outstanding thermal and mechanical properties, important for applications in different domains. X and Y are (in general) transition metal elements and Z is a main group element. Although X, Y and Z elements are metallic in solid form, many of the full-Heusler and half-Heusler systems turn out to be semiconductors or semimetals, or, at least, the respective Fermi energy is located very near to a gap in the electronic density of states. Such a scenario is a pre-requisite for capable thermoelectric materials.

In this Colloquium, we report on i) tuning of full-Heusler systems based on Fe2VAl by substituting appropriate elements on all lattice sites of the Cu2MnAl type structure and ii) on a deeper understanding of the resulting relevant electronic and thermal properties by combining experiments, carried out in a broad temperature range, and first principles calculations in terms of the density functional theory (DFT) using the package VASP.

Depending whether these materials are manufactured as bulk or as thin films, a variety of unexpected features, like meta-stable states, behaviours reminiscent of high entropy alloys, huge logarithmic derivatives of the electronic density of states or certain types of protected states are observed (both latter from DFT calculations), which might positively influence the thermoelectric behaviour of this family of compounds. Since thermal conductivity is further suppressed for the films - in comparison to the bulk material - the figure of merit, ZT, for such films turns out to be larger than values reported in literature [1].

Research supported by the “Christian Doppler Laboratory for Thermoelectricity” and the JST, program “MIRAI”.

[1]…B. Hinterleitner, et al., “Thermoelectric performance of a metastable thin-film Heusler alloy," Nature, vol. 576, no. 7785, pp. 85-90, 2019