Revisiting the structures and phase transitions of Ba₂NaNb₅O₁₅.

ABSTRACT: The room-temperature and low-temperature structure(s) of Ba₂NaNb₅O₁₅ (BNN) have been debated since the structure was proposed in the 1960s. This work revisits the structures and phase transitions of BNN, combining high-resolution X-ray and neutron powder diffraction with density functional theory calculations. Temperature-dependent high-resolution X-ray powder diffraction patterns are collected from 4 to 918 K, and sequential batch Rietveld refinement using a symmetry mode approach to describe the structure is used to extract the main structural changes as a function of temperature. The data show that the average structure of BNN is best described by the Ama2 space group, and no other structural phase transitions were observed below the ferroelastic

SUBMITTER: Grendal OG 

PROVIDER: S-EPMC10543678 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature