Jahn-Teller distortions in La1-xSrxCo1-yNiyO3-d perovskites

We suppose that accurate temperature dependent high-resolution X-ray powder diffraction (XPD) measurements in order to study an effects associated with Jahn-Teller (JT) distortions in La1-xSrxCo1-yNiyO3-d.
The combination of XPD results with our neutron diffraction [10] and Co K-edge XMCD data will give us the opportunity to establish the correlations between crystal and magnetic structure changes and clarify the origin of magneto-structural phase transition near the paramagnetic ->ferromagnetic ->antiferromagnetic transitions, as well as to provide an input for a novel modeling methods based on the density functional theory (DFT, DFT+U, DFT+U+SO) and the dynamic mean-field theory (DFT+DMFT). The calculations will allow us to gain new fundamental insights into the nature of AFM to FM phase transition by clarifying spin-states in each phase, i.e. compare of the Co3+(HS) + Co4+(IS) into Co3+(HS->IS->LS) + growth of cooperative JT effect Co4+(LS) or dynamic JT Co2+(LS) [9-11].