Search for crystallographic signatures of spin-crossover transition in the layered Ruddlesden–Popper-type cobalt oxychlorides Sr2CoO3Cl and

We propose to study the pressure effect on structure of the layered Ruddlesden–Popper-type cobalt oxychlorides Sr2CoO3Cl and Sr3Co2O5Cl2. These compounds are antiferromagnets with high Neel temperature TN>300 K. Co(3+) ions in these compounds are square-pyramidally coordinated and thus possess pure high-spin state. Application of high pressure might lead to spin-crossover transition to low-spin state changing the magnetic and electronic properties of material. Co(3+) cation takes the low-spin state being octahedrally coordinated. Thus, the structural evolution under pressure can provide a hint for spin-crossover transition. Combined with electronic transport measurements, Co Kβ X-ray emission spectroscopy and electronic structure calculations obtained results will allow to unravel the interplay between crystal structure and magnetic and electronic properties of Co-based perovskite-like materials.