Structural analysis of strained LaVO₃thin films

Abstract

While structure refinement is routinely achieved for simple bulk materials, the accurate structural determination still poses challenges for thin films due on the one hand to the small amount of material deposited on the thicker substrate and, on the other hand, to the intricate epitaxial relationships that substantially complicate standard X-ray diffraction analysis. Using a combined approach, we analyze the crystal structure of epitaxial LaVO3 thin films grown on (100)-oriented SrTiO3. Transmission electron microscopy study reveals that the thin films are epitaxially grown on SrTiO3 and points to the presence of 90• oriented domains. The mapping of the reciprocal space obtained by high resolution X-ray diffraction permits refinement of the lattice parameters. We finally deduce that strain accommodation imposes a monoclinic structure onto the LaVO3 film. The reciprocal space maps are numerically processed and the extracted data computed to refine the atomic positions, which are compared to those obtained using precession electron diffraction tomography. We discuss the obtained results and our methodological approach as a promising thin film structure determination for complex systems.

Preparation and characterisation of a novel agar oligosaccharide–iron (III) complex

“…XRD analysis is a structural analysis methodology used to evaluate the inner distribution of atoms, and it can reflect the crystal structure of materials (Rotella et al ., ). Figure c shows the XRD patterns of AOS, AOS–iron (III) and FeCl 3 .…”

Probing orbital ordering in LaVO3 epitaxial films by Raman scattering

“…1,13,14,[25][26][27] The low temperature phase is monoclinic P2 1 /b, with a rather larger change of the c-axis. The structure of LaVO 3 exhibits tilted VO 6 octahedra and displaced La ions (with respect to a pure perovskite structure), which in case of the bulk are relatively small and the lattice parameters can be related to a pseudocubic (PC) structure according to the relation:…”

“…27 Experimentally, so far only the structure and orientation of PrVO 3 and LaVO 3 films grown under compressive strain on SrTiO 3 (100) have been studied, and only domains with the c-axis lying in the plane of the SrTiO 3 substrate were found. 15,26,29 The orientation of the c-axis is very important for making the right choice of the polarization of the incident light in optical spectroscopy investigations. 19,20,30 To obtain more information on the epitaxial relationships between the films and the substrates and on the domain structure of the films, we performed transmission electron microscopy of cross sectional specimens.…”

“…26 High angle annular dark field (HAADF)-STEM images taken in two such domains are shown in Figs. 2(b) and 2(c).…”

Structure and orbital ordering of ultrathin LaVO3probed by atomic resolution electron microscopy and Raman spectroscopy

“…The temperature dependence of the Raman intensity is very similar to the temperature dependence we observed for the same Raman mode of epitaxial LaVO 3 films (55 nm thick) grown on DyScO 3 and LaGaO 3 substrates , indicating that OO sets in the LaVO 3 layers of the multilayer sample below ≈130 K. In contrast to single crystal samples that can be achieved in a single domain state, the phase transition of thin epitaxial LaVO 3 films is affected by the influence of the epitaxial growth conditions that lead to strain effects, domain formation and accommodations of the oxygen octahadra rotation patterns (see the SOM). Due to the unavoidable formation of domains of different orientations of the [001] O axis in epitaxial layers (see Fig. and also Fig.…”