fig3

Figure 3. Reciprocal space mapping (RSM) analysis of strain states in YBCO films. (A) YBCO/STO/SAO/STO heterostructure, showing the close overlap between the YBCO (1 0 9) and STO (103) peaks, confirming coherent epitaxial growth under strong substrate clamping; (B) Transferred flexible YBCO/PI film. The YBCO (1 0 8), (1 0 9), and (1 0 10) reflections exhibit a sharpened profile along the Qz axis (decreased strain gradient) and a distinct rightward broadening along the Qx axis (in-plane strain relaxation toward bulk lattice parameters). YBCO: YBa₂Cu₃O₇; STO: SrTiO₃; SAO: Sr₄Al₂O₇; PI: polyimide.