Bismuth telluride (BiTe) is one of the most important commercial thermoelectric materials. In recent years, the discovery of topologically protected surface states in Bi chalcogenides has paved the way for their application in nanoelectronics. Determination of the fracture toughness plays a crucial role for the potential application of topological insulators in flexible electronics and nanoelectromechanical devices. Using depth-sensing nanoindentation tests, we investigated for the first time the fracture toughness of bulk single crystals of BiTetopological insulators, grown using the Bridgman-Stockbarger method. Our results highlight one of the possible pitfalls of the technology based on topological insulators.

The authors acknowledge funding from PON MaTeRiA (No. PONa3_00370). A. P. thanks Elettra Sincrotrone Trieste S.C.p.A. for economic support. E. V. C. acknowledges funding from the University of Basque Country UPV/EHU (No. IT-756-13), the Departamento de Educación del Gobierno Vasco, the Tomsk State University Academic D. I. Mendeleev Fund Program (No. 8.1.05.2015), the Spanish Ministry of Economy and Competitiveness MINECO (No. FIS2013-48286-C2-1-P), Saint Petersburg State University (No. 15.61.202.2015).

Peer Reviewed