Transferred hyperfine interaction and structure i an coexisting phases:mA XRD and NMR-MAS study

X-ray diffraction (XRD) and (Formula presented) measurements have been performed on (Formula presented)(Formula presented) (lithium cationic fraction, x=0.333), (Formula presented)(Formula presented) (x=0.667), and the intermediate composition with x=0.40. The use of magic angle spinning produces complex manifolds of the spinning sidebands. The predominant interaction affecting the NMR spectrum is the transferred hyperfine coupling (TFHI) between the Mn ions and the Li spins. TFHI parameters are extracted from MAS-NMR spectra of oxides containing a large quantity of manganese. We obtained a full spectral assignment for the spinel (Formula presented)(Formula presented), for the rocksalt (Formula presented)(Formula presented), and for the x=0.40 sample, which contains the rocksalt and both stoichiometric and nonstoichiometric spinel phases. According to XRD data, the rocksalt phase contains three nonequivalent lithium sites whose NMR peaks are shifted upfield from x=0.667 to 0.40 because of the cell volume expansion.mThe (Formula presented) ions belonging to the two spinel phases of x=0.40 are quite mobile and give origin by motional narrowing to a single peak, which is slightly shifted upfield with respect to that of (Formula presented)(Formula presented).