Rare-earth-based cuprate superconductors belonging to the REBa₂Cu₃O₇−δ family have fascinated significant attention due to their extra ordinary properties. In the present study, the structural characteristics of chromium-doped ErBa₂Cu₃₋ₓCrₓO₇−δ (x = 0.2) superconductors were investigated using X-ray diffraction (XRD). The samples were synthesised using the solid-state reaction method. XRD analysis confirmed the formation of an orthorhombic crystal structure typical of the RE 123 superconducting phase. The calculated lattice parameters were a = 3.88 Å, b = 3.94 Å, and c = 11.75 Å, consistent with orthorhombic symmetry. The orthorhombicity value of 0.0076 showed well-ordered oxygen chains within the lattice. Crystallite sizes, estimated using the Scherrer equation, ranged from 14 nm to 106 nm, revealing nano crystalline features. Microstrain values varied between 0.0007 and 0.0059, reflecting lattice distortions induced by chromium substitution at copper sites. Overall, the findings of the study reveal that Cr doping introduces slight modifications to the microstructure while preserving the fundamental crystal structure of the Er 123 phase.
Rawat et al. (Thu,) studied this question.