Evidence for charge localization in the ferromagnetic phase of from high real-space-resolution x-ray diffraction

High real-space-resolution atomic pair distribution functions of (Formula presented) 0.25, and 0.33) have been measured using high-energy x-ray powder diffraction to study the size and shape of the (Formula presented) octahedron as a function of temperature and doping. In the paramagnetic insulating phase we find evidence for three distinct bond lengths which we ascribe to (Formula presented)-short, and (Formula presented)-long bonds, respectively. In the ferromagnetic metallic (FM) phase, for (Formula presented) and (Formula presented) we find a single Mn-O bond length; however, as the metal-insulator transition is approached either by increasing T or decreasing x, intensity progressively appears around (Formula presented) and in the region (Formula presented) suggesting the appearance of (Formula presented)-long bonds and short (Formula presented) bonds. This is strong evidence that charge localized and delocalized phases coexist close to the metal-insulator transition in the FM phase.