Determination of Solubility Characteristic of (Bi, Gd) Substitution in Bi-2223 Inorganic Materials

In this study, it is examined the significant variations in the superconducting, electrical and structural belongings of Bi-site Gd nanoparticle substituted Bi-2223 crystal. The Bi2.0-xGdxSr2.0Ca2.1Cu3.2Oy (0≤x≤0.3) materials obtained with the standard solid state reaction technique are characterized by dc resistivity (ρ-T), X-ray diffraction (XRD) and transport critical current density (Jc) measurements. Moreover, all experimental findings as regards room temperature resistivity, residual resistivity, critical transition temperatures (Tc onset − Tc offset ), crystallinity, lattice constant parameters, average crystallite size, phase fraction and strength quality of interaction between superconducting grains in the Bi-2223 ceramics declare that the structural, electrical and superconducting characteristics degrade systematically with the ascending of the Gd substitution level in the Bi-2223 samples. Furthermore, the major reason of the reduction trend observed especially in the electrical and superconducting features is in relation with the hole localization problem in the Cu-O2 layers. In this regard, grain boundary weak connections, dislocations and defects in the matrix considerably ascend with the enhancement of Gd nanoparticle substitution level. As seen from XRD measurements, it is clearly determined that there seems to be a decrement in the Bi2223 phase with the enhancement of Gd inclusions up to the substitution amount of x=0.1. After this critical point, new characteristics peaks of Gd2O3 appear and measurement findings rapidly diminish to the minimum values. This substitution level emphasizes that the solubility limit of Gd is noted to be x=0.1 for Bi-2223. Likewise, the regular decrement observed c-axis length, critical current density and grain size favors the regular retrogression of the superconducting characteristics.