Ac Magnetic Susceptibility and EPR Studies of (Co0.5Zn0.5Fe2O4)x/(Cu0.5Tl0.5)-1223 Composites

Abstract

Cobalt zinc ferrite nanoparticles (Co0.5Zn0. 5Fe2O4)x (∼5–8 nm in size) added to Cu0.5Tl0.5Ba2Ca2Cu3O10−δ superconductor samples, 0.00 ≤x≤ 0.20 wt. %, were prepared using a singlestep solid-state reaction technique. The temperature dependence of the real (χ′) and imaginary (χ″) components of the magnetic susceptibility (ACMS) was measured at various ac magnetic field amplitudes (3–16 Oe). The results were analyzed by using Bean critical state model to estimate the critical current density (Jc) It was found that Jc increases as x increases up to 0.08 and then it decreases with further increase in x. X- and Q-Band (9.3 and 33. GHz) electron paramagnetic resonance (EPR) spectra were measured in the temperature range from 300 to 10 K.The g values of Cu 2+ monomer were found to correspond to that of rhombic site symmetry with gxx = 2.21 ± 0.02, gyy = 2.10 ± 0.02, and gzz = 2.02 ± 0.02. © 2016, Springer Science+Business Media New York.