Solid state NMR spin-lattice relaxation investigation of oxygen dynamics in scandium doped ceria from 60 to 1073Â K

For 8-Sc, the high temperature process is assigned to hopping between potential wells with different energy minima with apparent activation energy of 0.28 eV. We have shown that in this case the apparent activation energy of the process does not correspond to barrier height for hopping, but to barrier height plus energy difference between minima of corresponding wells. The low temperature process is again a Raman process involving local vibrations with even lower characteristic energy 20 meV (160 cm− 1).