Insight into the dehydration behaviour of scandium-substituted barium titanate perovskites via simultaneous in situ neutron powder thermodiffractometry and thermogravimetric analysis
Artikel i vetenskaplig tidskrift, 2018

Hydration-dehydration cycles are critical to the mechanical performance of ceramic proton conductors. The development of in situ methods is desirable in order to study their structural response under conditions that mimic the operating ones. Neutron powder diffraction studies combined with simultaneous thermogravimetric analysis were performed on the hydrated forms of two members of the oxygen deficient perovskite BaTi1−xScxO3−δseries, with x = 0.5 and x = 0.7. Rietveld analyses agreed with in situ gravimetric data, allowing correlation of occupancy factors of the oxygen site to hydration levels and other structural data. Dehydration is an activated process that impacts on structural parameters and the level of Sc substitution was found to control the structural response during in situ dehydration, with higher Sc content leading to significantly greater volume contraction. This was rationalised by the chemical expansion due to hydration of oxygen vacancies within the x = 0.5 sample being anomalously small. Furthermore, the behaviour of the x = 0.5 system revealed an unexpected cell expansion during the early stages of dehydration, suggesting the hydration level may influence the thermal expansion coefficient (TEC).

Thermogravimetry

Proton conductor

Dehydration

Perovskite

Neutron powder diffraction

In situ

Författare

Nico Torino

Oorganisk miljökemi 2

Paul Henry

Rutherford Appleton Laboratory

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Christopher Knee

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

ESAB

Samantha K. Callear

Rutherford Appleton Laboratory

R. I. Smith

Rutherford Appleton Laboratory

Habibur Seikh Mohammad Rahman

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Sten Eriksson

Oorganisk miljökemi 2

Solid State Ionics

0167-2738 (ISSN)

Vol. 324 233-240

Ämneskategorier

Oorganisk kemi

Materialkemi

Farmakologi och toxikologi

DOI

10.1016/j.ssi.2018.07.010

Mer information

Senast uppdaterat

2018-11-05