Inelastic Neutron Scattering Study of the Proton Dynamics in Manganese Oxides: II . Proton Insertion in Electrodeposited

The inelastic‐neutron scattering spectra of partially reduced electrodeposited samples at 20 K are reported. Band decomposition in the 600 to 1200 cm−1 region reveals four components at almost fixed frequencies for all the samples. On the basis of their relative intensities for the different reduction rates, these components are assigned to: single protons in sites surrounded by empty sites at ∼750 cm−1 protons in sites nearest neighbor to the Mn4+ vacancies at ∼890 cm−1, protons in sites next nearest neighbor to the Mn4+ vacancies at ∼1010 cm−1, and, finally, at 1120 cm−1, protons further away from the vacancies in the ramsdellite/pyrolusite‐like channels of the intergrowth structure. All these sites are populated simultaneously, but at different rates, as the proton insertion degree increases. The variation of the integrated intensity of the four components with the reduction degree is discussed in terms of dynamical coupling with the charge compensating protons in the vacancies. The spectra in the 30 to 500 cm−1 region reveal different dynamical regimes for the lattice modes.