Microstructure and micromechanical properties of GaV4S8 ceramics prepared by single-step solid state synthesis

Abstract Despite the current focus on the electronic properties of GaV4S8 lacunar spinel, the microstructural and mechanical characterization of this material is scarce in the literature. In this work, we propose an effective GaV4S8 ceramics production method and provide a detailed microstructural and micromechanical characterization. Light microscopy, scanning electron microscopy and X-ray diffraction are used to describe the microstructure of the ceramic targets that can be used for thin film deposition. V2O3 was found to be the main impurity in ceramic targets and its content is discussed with respect to the sintering atmosphere control. Nanoindentation and microcantilever bending were employed to provide estimates of the indentation modulus, hardness and fracture stress of individual grains. The values of these parameters have been determined as Er = 130 ± 2 GPa, H = 8.9 ± 0.2 GPa and σc = 600 ± 57 MPa, respectively.