Local Order and Structure in Mn-Substituted Manganites Studied by EXAFS

We report extended X-ray absorption fine structure measurements at the Mn K edge on La0.25Ca0.75Mn0.92Cr0.08O3 samples. Macroscopically, the Mn substitution induces a short-range charge-ordered state in spite of the long-range one present in the parent manganite La0.25Ca0.75MnO3. We show how on a local scale the structural EXAFS parameters still confirm the presence, with only a slight reduction, of the features characteristic of the charge ordered un-substituted compounds.