55Mn NMR investigation of electronic phase separation in La1-xCaxMnO3 for 0.2 ≤ x ≤ 0.5

Mn-55 NMR line shape measurements in La1-xCaxMnO3 for 0.20 less than or equal to x less than or equal to 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.