Emergent behaviour in perovskites from symmetry breaking

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• Dr Nicholas Bristowe, Kent
• Friday 31 January 2020, 14:00-15:00
• Metallurgy and Materials, GA03.

If you have a question about this talk, please contact Andrew Morris.

Perovskites are of potential interest for numerous applications due to the wide range of functional physical properties they exhibit, from superconductivity to ferromagnetism, ferroelectricity and the photovoltaic effect. They are also an appealing system for fundamental study since one can introduce complexity in a systematic fashion. For example, the simple 5-atom ABX3 cubic perovskite structure, characterised by corner-sharing X6 octahedra, can not only host a range of elemental ions, but also organic molecular ions to form hybrid organic-inorganic frameworks. The structures are not only chemically diverse, but also structurally, and can exhibit various types of small structural distortions to the simple cubic, such as Jahn-Teller, octahedral tilting, breathing, polar, and anti-polar motions. Finally, perovskites can form layered structures, through either ionic or vacancy ordering, or ordered stacking arrangements to create the double perovskites, Ruddlesden-Popper, Aurivillius, Dion-Jacobson or Brownmillerite series. Each type (chemical, structural, layering) of complexity breaks the symmetry of the cubic parent ABX3 in a well-defined way. In this talk I will present a few striking examples of how just small deviations from the cubic perovskite symmetry can introduce striking changes in physical behaviour, and how the combination of first principles calculations and group-theory can provide helpful insight.

This talk is part of the Met and Mat Seminar Series series.

This talk is included in these lists:

• Met and Mat Seminar Series
• Metallurgy and Materials, GA03
• School of Metallurgy and Materials Colloquia

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