KIT | KIT-Bibliothek | Impressum | Datenschutz

High-Performance Thermomagnetic Generators Based on Heusler Alloy Films

Gueltig, Marcel 1; Wendler, Frank 1; Ossmer, Hinnerk 1; Ohtsuka, Makoto; Miki, Hiroyuki; Takagi, Toshiyuki; Kohl, Manfred 1
1 Institut für Mikrostrukturtechnik (IMT), Karlsruher Institut für Technologie (KIT)

Abstract (englisch):

Recent developments on Heusler alloys including Ni–Mn–X and Ni–Co–Mn–X (X = Ga, In, Sn,…) demonstrate multiferroic phase transformations with large abrupt changes in lattice parameters of several percent and corresponding abrupt changes in ferromagnetic ordering near the transition temperatures. These materials enable a new generation of thermomagnetic generators that convert heat to electricity within a small temperature difference below 5 K. While thermodynamic calculations on this energy conversion method predict a power density normalized to material volume of up to 300 mW cm−3, experimental results have been in the range of µW cm−3. Challenges are related to the development of materials with bulk-like single-crystal properties as well as geometries with large surface-to-volume ratio for rapid heat exchange. This study demonstrates efficient thermomagnetic generation via resonant actuation of freely movable thin-film devices of the Heusler alloy Ni–Mn–Ga with unprecedented power density of 118 mW cm−3 that compares favorably with the best thermoelectric generators. Due to the large temperature-dependent change of magnetization of the films, a periodic temperature change of only 3 K is required for operation. ... mehr

DOI: 10.1002/aenm.201601879
Zitationen: 70
Web of Science
Zitationen: 64
Zitationen: 71
Zugehörige Institution(en) am KIT Institut für Mikrostrukturtechnik (IMT)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2016
Sprache Englisch
Identifikator ISSN: 1614-6832, 1614-6840
KITopen-ID: 1000062636
HGF-Programm 43.22.01 (POF III, LK 01) Functionality by Design
Erschienen in Advanced energy materials
Verlag Wiley-VCH Verlag
Band 7
Heft 5
Seiten Art.Nr. 1601879
Vorab online veröffentlicht am 18.11.2016
Nachgewiesen in Dimensions
Web of Science
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page