NMR on 55Mn in the ferromagnetic Ni-substituted manganite La0.6Pb0.4Mn0.86Ni0.14O3

NMR on 55Mn in the single-crystal manganite La0.6Pb0.4Mn0.86Ni0.14O3 (T C =242 K), which exhibits metallic conductivity below T C , is investigated in the temperature range 61–215 K. At low temperatures, together with a line corresponding to the averaged hyperfine field at the 55Mn nuclei (the averaging is due to the motion of electronic holes along Mn sites), the NMR spectrum also contains two lines corresponding to localized states Mn4+ and Mn3+. In the temperature range 100–200 K it is found that the complicated NMR spectrum is transformed into a single line on account of a delocalization of the holes in the e g orbitals of manganese. A comparison of the NMR data with the temperature dependence of the resistivity suggsets that a wide distribution of charge-carrier mobilities exists in the crystal.