Strong orbital correlations in a Fe-substituted spin-glass-manganite

Abstract

The compound ${\mathrm{La}}_{0.66}{\mathrm{Ba}}_{0.40}{\mathrm{Mn}}_{0.61}{\mathrm{Fe}}_{0.33}{\mathrm{O}}_{3}$ shows anisotropic magnetic correlations with no long-range order. Specific heat measurements suggest these correlations represent the bulk. Orbital correlations of ${\mathrm{Mn}}^{3+}{e}_{g}$ electrons, surviving in an environment of largely disordered exchange interactions, are invoked to account for this magnetic state. These results argue in favor of a strain-field mechanism for orbital ordering in manganites.