Crystal structure investigation of La_5.4W_1-yMo_yO_12-δ for gas separation by high-resolution transmission electron microscopy.

ABSTRACT: Lanthanum tungstate (LWO) and LWO with 20 at.% and 35 at.% molybdenum substituting tungsten were prepared by the Pechini method. Phase purity and successful Mo substitution inside these dense LWO membrane materials were confirmed by conventional and high resolution transmission electron microscopy techniques. The split of La₂/W₂ site by around 0.3 Å was proven. Extra reflections show up in the diffraction patterns from Mo-substituted LWO, and together with simulations, these reflections were recognized as forbidden reflections in a non-substituted LWO system, while the extinction rules are broken by Mo substitution due to the different scattering factors of W and Mo. Energy-dispersive X-ray chemical mapping allowed direct visualization of individual atomic columns, an

SUBMITTER: Ran K 

PROVIDER: S-EPMC6397252 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature