Multi-slice frozen phonon simulations of high-angle annular dark field scanning transmission electron microscopy images of the structurally and compositionally complex Mo–V–Nb–Te oxide catalyst

Abstract

We report frozen phonon multi-slice image simulations for the complex oxidation catalyst M1. Quantitative analysis of the simulations suggests that the detailed order of the cations along the electron propagation direction in a [001] zone axis orientation can lead to different high-angle annular dark field signals from atomic columns with identical composition. The annular dark field signal varies linearly with atomic percent V, and the spread of intensities due to the atomic species order is of similar magnitude to the intensity difference due to ± 5% V.

Continuously tunable ferroelectric domain width down to the single-atomic limit in bismuth tellurite

“…The HAADF-STEM image simulations were conducted by using QSTEM software based on frozen phonon multi-slice methods 60 . The parameters used were set according to the experiment conditions, which is shown as follows: acceleration voltage is set as 300 kV, the spherical aberration Cs is set as 0 nm, the semi convergence angle is set as 21.4 mrad, the defocus is set as 0 nm, the source size is of 0.8 Å and the chromatic aberration Cc is set as 1 mm.…”

Study of super-efficient defective MoVSbO catalysts used for ethane oxidative dehydrogenation by HAADF-STEM and of their thermal evolution by environmental electron microscopy and tomography

“…It initially allowed the structure of the M1 phase to be solved and the morphology of the M1 phase particles to be characterized. 32,33 It was then used to study the spatial distribution of the constitutive elements on the different crystallographic sites [34][35][36][37][38][39][40][41][42][43] and the intergrowth of M1 phase with phase M2 or with the typical Mo 5 O 14 phase. 44 It was finally used to investigate in situ the modifications of structure under conditions of catalytic reducing reactions.…”

Probing Compositional Order in Atomic Columns: STEM Simulations Beyond the Virtual Crystal Approximation

“…Previously, we published the results of frozen-phonon multislice STEM image simulations of the complex Mo–V–Nb–Te–O (amm) oxidation catalyst commonly referred to as “M1” (Blom & Vogt, 2018). This compound is an orthorhombic oxide bronze with 11 distinct cations sites forming cation–oxygen atomic columns along the c -axis in the framework and two additional intercalated cations in hexagonal and heptagonal channels of the structure.…”