Dresden 2017 – wissenschaftliches Programm
DS 17.1: Vortrag
Montag, 20. März 2017, 17:45–18:00, CHE 89
Thermal conductivity of Half-Heusler superlattices — Paulina Komar1,3, Niklas Reuter1, Emigdio Chavez-Angel1, Sven Heinz1,3, Benjamin Balke2, and •Gerhard Jakob1,3 — 1Institute of Physics, Johannes Gutenberg University Mainz, 55099 Mainz, Germany — 2Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University Mainz, 55099 Mainz, Germany — 3Graduate School Materials Science in Mainz, 55128, Germany
Variable designs of TiNiSn/HfNiSn superlattices (SLs) and nonperiodic multilayers were investigated to find the most effective way to reduce the crossplane thermal conductivity κ at room temperature. The latter property was determined using a differential 3ω method. The research started from investigation of the relation between κ and the SL period while keeping the ratio of the two materials in the SL period equal to unity. To obtain information exceeding that from the bare interface density, a series of films with varying layer thickness ratios was investigated. Moreover, we discuss the design of non-periodic multilayers and their influence on the thermal conductivity. For the latter materials we developed a software to simulate x-ray diffraction patterns of non-periodic structures.
The main conclusion is that the nanostructuring helps to reduce the thermal conductivity and contributes to enhanced figure of merit ZT compared to bare TiNiSn and HfNiSn films.
We gratefully acknowledge financial support by DFG (Ja821/4-2) and the Graduate School of Excellence Material Science in Mainz (GSC 266).