Multifunctional properties in Heusler compounds: from thermoelectric, topological insulators to spintronics
Prof. Dr. Claudia Felser
(Uni Mainz, IEEE Distinguished Lecturer)
05.05.2010
The rational design of new functional materials is the dream of every materials scientist. Precondition for the development of a design scheme is a structure type, in which many interesting properties can be found. An important class of materials with potential for applications in electronic devices and green energy are those of the Heusler and half-Heusler families. The latter are ternary semiconductors XYZ which exhibit the C1b structure: more than 250 compounds, nearly all semiconductors, are known to take up this structural type [1]. Of particular interest the band gap can be tuned from almost 4 eV to zero. Thus, thesematerials have attracted attention as potential candidates for both solar cell (wide band gap), thermoelectric applications (low band gap) and topological insulators [2]. The Heusler compounds X2YZ have been explored recently in the context of spintronics [3]. Some Heusler compounds have been demonstrated to be half-metallic ferromagnets in which the conduction electrons are almost fully spin polarized [4]. Moreover, these materials exhibit very high Curie temperatures. Superconductivity was found in several compounds [5].
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[2] S. Chadov, X.-L. Qi, J Kübler, G. H. Fecher, C. Felser, S.-C. Zhang, Nature Materials accepted, arXiv:1003.0193
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