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Local structural properties of 0.5BiMnO3-0.5ATiO3 (A = Ba or Sr)
Stefan T Norberg1, Stephen Hull, Roland Mathieu
1The ISIS Facility, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire, UK OX11 0QX. stn@chalmers.se
Chemical Communications (Cambridge, England)
|February 18, 2010
Summary
Neutron scattering reveals local structural disorder in bismuth titanate materials. Bismuth cations exhibit asymmetric coordination influenced by lone-pair electrons, differing from the average crystal structure.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Crystallography
Background:
- Bismuth titanate (BiMnO3-ATiO3) perovskites are of interest for their unique structural and electronic properties.
- Understanding local atomic arrangements is crucial for tuning material functionalities.
Purpose of the Study:
- To investigate the local and long-range atomic structure of 0.5BiMnO3-0.5ATiO3 (A = Ba, Sr) solid solutions.
- To identify deviations between average and local structural parameters.
Main Methods:
- Neutron total scattering experiments were performed.
- Reverse Monte Carlo (RMC) modeling was employed to analyze the scattering data.
Main Results:
- Local structural disorder was observed, significantly differing from the average crystal structure.
- Bismuth (Bi3+) cations were found to prefer asymmetric coordination environments.
- The asymmetric coordination of Bi3+ is attributed to the influence of its lone-pair electrons.
Conclusions:
- The study highlights the importance of local structure in understanding bismuth titanate materials.
- Lone-pair electrons on Bi3+ play a critical role in determining local coordination and structural asymmetry.
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