55MnNMR Investigation of Electronic Phase Separation inLa1−xCaxMnO3for0.2≤x≤0.5

${}^{55}\mathrm{Mn}$ NMR line shape measurements in ${\mathrm{La}}_{1-x}{\mathrm{Ca}}_x{\mathrm{MnO}}_3$ for $0.20\le x\le 0.50$ provide experimental evidence about the existence of two distinct regions in the $T-x$ magnetic phase diagram, where the homogeneous ferromagnetic (FM) metallic state is separated into FM metallic and FM insulating regions. These results are in agreement with recent theoretical predictions, which reveal a novel electronic phase separation in two FM states, providing orbital ordering and Jahn-Teller phonons are taken into consideration.