“…It is explained usually by presence of various crystal lattice defects (dislocations, stacking faults, twin boundaries), as well as non-superconducting phases or those with lower T c . These phases may arise due to the local chemical composition fluctuations involving the LRE 3+ for Ba 2+ substitution and LRE123ss formation [4,23,24]. Oxygen-deficient regions also might be responsible for magnetic field pinning [25].…”