Infrared Spectroscopy and Excess Conductivity Analysis for (Y3Fe5O12)x/Cu0.5Tl0.5Ba2Ca2Cu3O10-δ Composites

Abstract In this study, the influence of adding Yttrium iron garnet (Y 3 Fe 5 O 12 ) nanoparticles (NPs) on the microstructure and fluctuation-induced conductivity (FIC) of Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10-δ (CuTl-1223) superconductor was studied. Y 3 Fe 5 O 12 NPs were produced by the co-precipitation technique. By solid state route, (Y 3 Fe 5 O 12 ) x /Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10-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 (Y 3 Fe 5 O 12 ) x /Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10-δ composites were found to be invariable with Y 3 Fe 5 O 12 content. The volume fraction of the host phase was increased with Y 3 Fe 5 O 12 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 (T 0 ). 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 ζ c (0), interlayer coupling (J), and anisotropy parameter (γ) were estimated from the Lawrence–Doniach (LD) model as a function of Y 3 Fe 5 O 12 content.