Hybrid reflections from multiple x-ray scattering in epitaxial oxide films

Abstract

In numerous symmetric h-2h scans of phase-pure epitaxial complex oxide thin films grown on single-crystal substrates, we observe x-ray diffraction peaks that correspond to neither the film nor the substrate crystal structure. These peaks are the result of multiple, sequential diffraction events that occur from both the film and the substrate. The occurrence of so-called "hybrid" reflections, while described in the literature, is not widely reported within the complex oxide thin-film community. We describe a simple method to predict and identify peaks resulting from hybrid reflections and show examples from epitaxial complex oxide films belonging to three distinct structural types.

Full Control of Polarization in Ferroelectric Thin Films Using Growth Temperature to Modulate Defects

“…θ‐2θ diffractograms along (001) and (002) (see, Figure a; Figures S2 and S3, Supporting Information), display Laue oscillations attesting again the high crystalline quality of the films. Interestingly, on many of our diffractograms along (002), we observe an additional peak close to 2θ = 45.3° (see, for example, the blue diffractograms in Figure 4a): this peak is due to double diffraction [ 38,39 ] and is a consequence of our atomically smooth interfaces. From the 2θ position of the film peak and from the Laue oscillations, one can determine the c ‐axis lattice parameter and thickness of the films.…”

Hybrid reflections from multiple x-ray scattering in epitaxial bismuth telluride topological insulator films

“…Hybrid reflections (HRs) from multiple x-ray diffraction are known to cause extra features in diffraction data of thin films. In general, they can be easily avoided or identified by changing the sample azimuth [1], or they can be used as a tool for studying heteroexpitaxial films [3][4][5][6][7] and superlattices [8]. In a new class of epitaxial systems with potential applications in spintronic and quantum computation, film and substrate materials have quite different lattices [9][10][11][12].…”

“…Structure refinement by XRD simulation is the most used approach for accurate data analysis, which is only as reliable as the quality of the best achieved fit of the data. To this purpose, all features (peaks in intensity) in a scan of intensity must be identified [1]. Any disagreement between experimental and simulated data call into question the actual structure of the thin film [2].…”

Lateral lattice coherence lengths in thin films of bismuth telluride topological insulators, with overview on polarization factors for X-ray dynamical diffraction in monochromator crystals

“…Hybrid reflections have been studied and applied to investigate heteroepitaxial systems since 1981. [18][19][20][21][22][23][24][25][26][27][28][29] However, only recently their occurance in epitaxial systems of hexagonal ( 001 how to measure such hybrids can be found elsewhere. 30 The split of a hybrid pair as function of the rocking curve angle θ is proportional to ∆a/a as given by ∆θ…”