High-performance and low-cost composites are engineers’ dream for technological applications. To fulfill the material for an engineering application, it is important to understand the mechanical properties of the material. The primary goal of this research is to investigate the impact of nano-sized Yttrium iron garnet (Y3Fe5O12) addition on the microstructure and mechanical properties of the polycrystalline Cu0.5Tl0.5Ba2Ca2Cu3O10-δ (CuTl-1223) superconductor. Co-precipitation and solid-state reaction methods were utilized to prepare Y3Fe5O12 nanoparticles and Cu0.5Tl0.5Ba2Ca2Cu3O10-δ superconductor, respectively. (Y3Fe5O12)x/Cu0.5Tl0.5Ba2Ca2Cu3O10-δ nanoparticle/superconductor composites were formed by adding small contents of Y3Fe5O12 (x = 0.00, 0.02, 0.04, 0.06, 0.08, and 0.10 wt%) to the CuTl-1223 matrix. The volume fraction percentage of the main phase, CuTl-1223, was increased from 87.9 to 91.4% as x was adjusted from 0.00 to 0.04 wt%. The unit cell parameters (a and c) remained unchanged following the addition of Y3Fe5O12 nanoparticles to the host CuTl-1223. The porosity percentage (P %) was decreased from 39.1 to 29.4% as x was increased from 0.00 to 0.10 wt%. Thus, the addition of Y3Fe5O12 nanoparticles has the ability to reduce weak links and voids among the CuTl-1223 superconducting grains. The grain morphology for the prepared composites was identified through scanning electron microscopy. The different elemental compositions were detected by energy-dispersive X-ray measurements. Vickers microindentation hardness test was employed to study the mechanical strength of the prepared composites. Analysis and modelling of Vickers hardness (Hv) versus test load (F) were done through various models. Meyer’s empirical law showed that all the prepared composites follow normal indentation size effect behaviour. Hays and Kendall model clarified that the applied test load was sufficient to produce both elastic and plastic deformation for the investigated samples. The elastic/plastic deformation model indicated that the prepared samples contain an elastic relaxation portion that recovers after withdrawing the test load. The proportional sample resistance and modified proportional sample resistance models confirmed the HK model findings. Moreover, the HK model was found to be the most suitable model for describing the microhardness results of the prepared samples. Furthermore, the elastic modulus (E), yield strength (Y), fracture toughness (K) and brittleness index (B) for the prepared composites were calculated as function of Y3Fe5O12 addition.

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In this study, the influence of adding Yttrium iron garnet (Y3Fe5O12) nanoparticles (NPs) on the microstructure and fluctuation-induced conductivity (FIC) of Cu0.5Tl0.5Ba2Ca2Cu3O10-δ (CuTl-1223) superconductor was studied. Y3Fe5O12 NPs were produced by the co-precipitation technique. By solid state route, (Y3Fe5O12)x/Cu0.5Tl0.5Ba2Ca2Cu3O10-δ composites, with x = 0.00, 0.02, 0.04, 0.06, 0.08, and 0.10 wt. % were prepared. The tetragonal unit cell parameters of (Y3Fe5O12)x/Cu0.5Tl0.5Ba2Ca2Cu3O10-δ composites were found to be invariable with Y3Fe5O12 content. The volume fraction of the host phase was increased with Y3Fe5O12 addition till x = 0.04 wt. %. The different vibrational modes of the samples were identified through Fourier transform infrared spectroscopy (FTIR). The transition from normal to the superconducting state, for the prepared composites, was done through d.c resistivity measurements from room temperature down to zero critical temperature (T0). The Aslamazov–Larkin (AL) model was used to examine fluctuation regions in resistivity-temperature curves. At high temperatures, short wave fluctuation was observed. A cross-over between short wave fluctuation and the mean-field region was spotted at lower temperatures. The mean field region for the examined composites was composed of two-dimensional fluctuations along with one-dimensional fluctuation. The coherence length along the c-axis ζc(0), interlayer coupling (J), and anisotropy parameter (γ) were estimated from the Lawrence–Doniach (LD) model as a function of Y3Fe5O12 content.