Evaluation of Degree of Orientation in Metal and Oxide Epitaxial Thin Films by Using Reciprocal Space Mapping

Abstract

The degree of orientation of mixed a- and c-axis-oriented epitaxial thin films was defined. This can be evaluated using several scanning methods in X-ray diffraction. Reciprocal space mapping was chosen because it is adaptable to the modulations of lattice spacing, as well as the small modulations of orientation. The proposed method was demonstrated for superconducting YBa₂Cu₃O_7–δ and magnetic FePt thin films. The increasing tendency of the degree of orientation with increasing deposition temperature agreed with those obtained from the pole figure measurements. The degree of orientation was used to evaluate the order parameter of the FePt film with overlapping sublattice and fundamental peaks. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.