We have studied the chemical potential shift in La(1-x)Sr(x)MnO(3) as a
function of doped hole concentration by core-level x-ray photoemission. The
shift is monotonous, which means that there is no electronic phase separation
on a macroscopic scale, whereas it is consistent with the nano-meter scale
cluster formation induced by chemical disorder. Comparison of the observed
shift with the shift deduced from the electronic specific heat indicates that
hole doping in La(1-x)Sr(x)MnO(3) is well described by the rigid-band picture.
In particular no mass enhancement toward the metal-insulator boundary was
implied by the chemical potential shift, consistent with the electronic
specific heat data.Comment: 7 pages, 3 figures, to be published in Europhysics Letter
