Subamorphous thermal conductivity of crystalline half-Heusler superlattices
Chávez Ángel, Emigdio (Johannes Gutenberg-Universität Mainz. Institut für Physik)
Reuter, N. (Johannes Gutenberg-Universität Mainz. Institut für Physik)
Komar, P. (Johannes Gutenberg-Universität Mainz. Institut für Physik)
Heinz, Sven (Johannes Gutenberg-Universität Mainz. Institut für Physik)
Kolb, U. (Johannes Gutenberg-Universität Mainz. Institut für anorganische und analytische Chemie)
Kleebe, H. J. (Technische Universität Darmstadt. Institut für Angewandte Geowissenschaften)
Jakob, Gerhard (Johannes Gutenberg-Universität Mainz. Institut für Physik)

Date:	2019
Abstract:	The quest to improve the thermoelectric figure of merit has mainly followed the roadmap of lowering the thermal conductivity while keeping unaltered the power factor of the material. Ideally an electron-crystal phonon-glass system is desired. In this work, we report an extraordinary reduction of the cross-plane thermal conductivity in crystalline (TiNiSn):(HfNiSn) half-Heusler superlattices (SLs). We create SLs with thermal conductivities below the effective amorphous limit, which is kept in a large temperature range (120-300 K). We measured thermal conductivity at room temperature values as low as 0. 75 W m⁻¹ K⁻¹, the lowest thermal conductivity value reported so far for half-Heusler compounds. By changing the deposition conditions, we also demonstrate that the thermal conductivity is highly impacted by the way the single segments of the SL grow. These findings show a huge potential for thermoelectric generators where an extraordinary reduction of the thermal conductivity is required but without losing the crystal quality of the system.
Note:	En publicar-se l'article, l'autor Emigdio Chávez treballa a l'Institut Català de Nanociència i Nanotecnologia
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Ultralow thermal conductivity ; Superlattices ; Amorphous limit of thermal conductivity
Published in:	Nanoscale and microscale thermophysical engineering, Vol. 23, issue 1 (August 2019) , p. 1-9, ISSN 1556-7273

DOI: 10.1080/15567265.2018.1505987

Postprint 36 p, 2.1 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles