Mechanical properties of polycrystalline RuSr2GdCu2O8 superconductor

The main objective of this paper is to report the room temperature hardness and elastic modulus of the RuSr2GdCu2O8 superconductor phase by instrumented indentation. Polycrystalline samples were produced by a solid state reaction technique. The samples were also characterized by scanning electron microscopy, X-ray diffraction and electrical resistivity measurements. The influence of porosity on the mechanical properties was avoided by considering only those indentations inside the grains. The hardness and elastic modulus were 8.6 GPa and 145 GPa, respectively. These values are comparable with those of Y-123. The indentation fracture toughness evaluated after conventional Vickers indentation was 1.9 MPa m1/2.

Research highlights
► Hardness and elastic modulus of Ru-1212 phase measured by instrumented indentation are reported.
► Polycrystalline samples were produced by a solid state reaction technique.
► Samples were also characterized by SEM, XRD and electrical resistivity measurements.
► Hardness and elastic modulus were 8.6 GPa and 145 GPa, respectively.
► These values are comparable with those of Y-123.