Phase separation and the possibility of orbital liquid states in CMR manganites. A 139La NMR study

139La NMR spin-lattice relaxation rate 1/T1 and rf enhancement experiments provide evidence that the low temperature regime of the ferromagnetic (FM) phase of La1-xCaxMnO3 segregates into highly-conductive and poorly-conductive FM regions, associated with differences in the orbital structure. Remarkably, phase separation is accompanied with the appearance of an extra NMR signal from FM regions with vanishingly small magnetic anisotropy. This feature has been attributed to the appearance of regions with strong orbital fluctuations, resembling droplets of an orbital liquid within the inhomogeneous FM matrix.