Transition metal chemistry meets the perovskite structure

English Abstract:

The perovskite structure is remarkably versatile, incorporating more than half of the stable elements in the periodic table. The wide range of chemical and structural variations as well as possibilities for non-stoichiometry gives rise to a wealth of interesting physical properties, many with important commercial applications. Transition elements in particular provide the capability for variations in oxidation and spin state, enhancing possibilities for transformations brought about by changes in environmental variables such as pressure, temperature or oxygen fugacity. In a similar way that ionic radii provide a simple compositional guide to the stability of perovskite structure variants, crystal field theory can provide an indication of the stable electronic configuration of transition element cations. The lower mantle mineral bridgmanite offers multiple possibilities for iron (two sites times two oxidation states times three spin states) which has complicated the interpretation of results from experimental studies. The presentation will focus on crystal field theory analysis applied to recent bridgmanite data acquired at high pressures and high temperatures to elucidate the state of iron in the deep Earth’s interior.