Ionicthermocurrent Studies of Mn++-Vacancy Complexes Associated with F- Ion in NaCl: (Mn++-V)F-

Abstract

The structure and the dipolar reorientation of Mn ++ -Vacancy complex, (Mn ++ -V), have been studied with the measurements of electron paramagnetic resonance (EPR) and ionic thermocurrent (ITC) in NaCl doubly doped with Mn ++ and F - ions. A new EPR signal of Mn ++ -F - complex with a vacancy at the nearest neighbor cation site (nn) was observed (Spectrum III 1F ) in addition to the one with a vacancy at the next nearest site (nnn) observed by Yokozawa and Kazumata (Spectrum III 2F ). ITC studies indicate that the orientation energies of a vacancy around Mn ++ -F - axis are 0.50, 0.53 and 0.58 eV in contrast to 0.67 eV for the orientation of Mn ++ -vacancy complex. Three ITC activation energies are attributed to the corresponding jumps from nn to nn around Mn ++ -F - axis, from nn to nnn and from nnn to nn site, respectively. Energy states for a vacancy around Mn ++ -V complex and (Mn ++ -V) F - are schematically shown.