Cation ordering schemes in perovskites. From left to the right: rock salt, layered and columnar ordering are shown for $B$-site ordering in $A_{2} B B^{\prime} \mathrm{O}_{6}$ perovskites.
Cation ordering schemes in perovskites. From left to the right: rock salt, layered and columnar ordering are shown for B-site ordering in A_{2} B B^{\prime} \mathrm{O}_{6} perovskites.