Investigation of the influence of grain boundary on the magnetic and transport properties of superconducting ceramics
A. N. Rouver, C. A. C. Passos, M. T. D. Orlando, J. N. O. Pinto Β· 2014
ππ΅π2πΆπ’3π7-πΏ polycrystalline ceramic samples were produced in order to study the thermal diffusivity.The samples were heat treated at different levels.These samples were characterized by XRD, ac magnetic susceptibility and scanning electron microscopy.The analyzes of the SEM image showed that the samples have different sizes of the junctions of grains.Samples A and B show ππ equal to 91.3 K and 91.3 K, respectively.EDS analyzes indicated the concentration of ions in the center of the grain and edge grain for each sample.The measurements of thermal diffusivity, performed by flash method, indicated that the sample has a larger grain size, sample A, also has higher thermal diffusivity.Sample A also showed better magnetic shielding in the ac magnetic susceptibility measurements.