Structural Modulation in Oxygen Deficient Epitaxial Bi₂Sr₂Ca₁Cu₂O_X Observed by X-ray Reciprocal Space Mapping

Abstract

X-ray reciprocal space mapping (XRSM) was employed to investigate the effect of oxygen deficiency on supercell (SC) modulation in an epitaxial Bi2Sr2Ca1Cu2O x (Bi-2212) single layer. Cross section XRSM (ω–2θ plane) was used to estimate both the lattice constants and SC periodicity in epitaxial Bi-2212, and plan view XRSM (ω–ψ plane) to verify the symmetry of an in-plane SC structure. The SC periodicity expanded along both the b- and c-axes on the Bi-2212 film post annealed in nitrogen atmosphere.

Effect of oxygen pressure on structural modulation observed by X-ray reciprocal space mapping in epitaxial bismuth cuprate superconducting film

“…In this work, the SC periodicity expanded on films deposited even at higher oxygen pressure. The previous study [13] showed that SC periodicity expanded on oxygen-deficient Bi-2212 film. A possible explanation for the expansion of SC periodicity along both b and c axes is that the film was deposited under the condition of oxygen deficiency; even though the film was deposited at higher oxygen pressure, fewer ions exposed to the substrate resulted in oxygen-deficient condition.…”

“…Recently, the XRSM method was used to investigate the SC structure in Bi-2212 films. Asymmetric distribution of satellite peaks generated by the SC structure was observed on XRSMs in epitaxial Bi-2212 thin films [12,13]. The influence of the SC periodicity on internal strain was also investigated on multilayered bismuth cuprate [14].…”

“…By re- placing ions with aliovalent ions, other effects such as inducing extra oxygen, might affect the SC structure on aliovalent substitution. To emphasize the effect of strain, multilayers of Bi-2212/Bi-2201 were examined by XRSM in order to evaluate the SC structure [13]. The authors reported that the SC structure expanded with expansion of the lattice constant along the c-axis while the SC structure contracted with contraction of the lattice constant, b.…”