S. Adler, J. Reimer, J. Baltisberger
Jan 26, 1994
Citations
2
Influential Citations
69
Citations
Journal
Journal of the American Chemical Society
Abstract
Oxygen-17 magnetic resonance, in conjunction with high-temperature X-ray diffraction (XRD) and differential thermal analysis (DTA), were used to investigate the structure of Ba[sub 2]In[sub 2]O[sub 5] and the dynamics of oxygen ion motion between room temperature and 1200[degrees]C. NMR and thermal analysis demonstrate that at 925[degrees]C there is an order-disorder transition which involves oxygen atoms between layers of octahedrally coordinated indium atoms. Both NMR and X-ray diffraction show that the material retains an orthorhombic (layered) structure until approximately 1075[degrees]C, at which point the material becomes cubic. The number of mobile oxygen atoms in the structure increases continuously between 925 and 1075[degrees]C, and only above 1075[degrees]C does the full population of anions become mobile. These results imply that vacancies contribute to transport two-dimensionally within the tetrahedral layers at the order-disorder transition. 26 refs., 13 figs.