Fig. 2: Crystal and surface quality of released and transferred TiO2 single-crystal nanomembrane (NM).

a Symmetric 2\(\theta -\omega\) scan. b Reciprocal space mapping around (112) reflection of as-grown TiO2 epitaxial films and TiO2 single-crystal NM released on supporting layer and transferred on Si substrates. The high-resolution X-ray diffraction measurements show single-crystallinity with uniform out-of-plane orientation and no in-plane rotation in released and transferred TiO2 NM. c EBSD maps of the as-grown TiO2 epitaxial films on VO2/TiO2 substrates (top) and transferred TiO2 NM on Si substrates (bottom), confirming the single-crystalline out-of-plane orientation. d Photograph of 40-nm-thick TiO2 single-crystal NM released on mechanical support with the identical lateral dimension with TiO2 host substrates. e OM image of transferred TiO2 NM on the carbon TEM grid. f AFM image of as-grown TiO2 films and transferred TiO2 NM, which confirms a uniform and flat surface without surface cracks or residues.