Poster Presentation 26th ACMM “2020 Visions in Microscopy”

Micromechanical testing of GaV4S8 ceramics (#218)

Jan Maňák 1 , Karel Tesař 1 , Jiří Hlinka 1
  1. Institute of Physics of the Czech Academy of Sciences, Prague, PRAGUE, Czech Republic

New advances in the research of lacunar spinels open interesting new possibilities for future computing technologies, especially since some of these materials are exhibiting low-temperature magnetic ordering with skyrmion phases. For a successful design of hardware parts using these materials, it is needed to fully characterise their mechanical properties. In present work, we investigate room temperature micromechanical properties of the GaV4S8 sintered ceramics by in-situ nanoindentation technique. The fracture mechanics is studied by microcantilever bending test in scanning electron microscope. Microcantilevers with triangular cross-section are fabricated by focused ion beam. Each microcantilever is positioned in a single grain and electron backscatter diffraction is used to determine its crystal orientation. The influence of the crystal orientation on the fracture mechanics is discussed. The dependence of nanohardness and elastic modulus on crystal orientation and the size effect is also analysed. The results show that this material has rather low fracture strength and nanohardness even at the room temperature and therefore, the design of possible parts out of this material should carefully address this issue.