Exploring the local structure of carbonate minerals to shed light on the carbon cycle

Carbonate minerals are present not only in the Earth crust, but even in the deeper part of our planet, being involved in the carbon cycle. In this view, we selected BaCO3 (witherite) and SrCO3 (strontianite), which exhibit the RT structure of aragonite. Upon temperature increase, these two minerals show phases transitions, that for now, were studied only taking into account the average structure. Interestingly, no structural analysis on the local structure by Pair Distribution Function (PDF) has ever been considered .To determine a link between the local structure and their behaviours upon heating, we propose an investigation using total scattering data collection. BaCo3 and SrCO3 will be investigated as well as their calcium counterpart (calcite and aragonite). Results will allow us to obtain a structural characterization of the average and local structure giving new insight into the evolution of these minerals as a function of the temperature and their role in the carbon cycle.