Abstract
(Co0.5Zn0.5Fe2O4)(x)/Cu0.5Tl0.5Ba2Ca2Cu3O10-delta samples, 0.00 <= x <= 0.20 wt%, were synthesized using a one-step solid-state reaction technique. Co0.5Zn0.5Fe2O4 nanoparticles were examined using X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). All prepared samples were characterized using XRD, scanning electron microscopy, (SEM) and electrical resistivity measurements. Vickers microhardness measurement for (Co0.5Zn0.5Fe2O4)(x)/Cu0.5Tl0.5Ba2Ca2Cu3O10-delta samples was carried out at room temperature under different applied loads varying from 1 to 10 N. Vickers microhardness (H-V) increases as x increases up to 0.08 wt%, and then it decreases with further increase in x. In addition, Vickers microhardness shows its dependence on the holding time of the indenter under applying constant loads. All samples exhibit indentation size effect (ISE) with normal trend, as Vickers microhardness decreases by increasing the applied loads. Different models were used to analyze the obtained results such as Meyer's law, Hays-Kendall (HK) approach, elastic/plastic deformation (EPD) model, proportional specimen resistance (PSR) model, and modified proportional specimen resistance (MPSR) model. The experimental results of Vickers microhardness are well fitted according to the MPSR model. Some important mechanical parameters such as Young's modulus (E), yield strength (Y), fracture toughness (K-f), and brittleness index (B-i ) were calculated as a function of Co0.5Zn0.5Fe2O4 nanoparticle addition. These parameters depend on the weight percent addition of Co0.5Zn0.5Fe2O4 nanoparticles into Cu0.5Tl0.5-1223 phase.