An investigation of the ground state of Mn3+in MgO based on thermal conductivity measurements

Measurements of the thermal conductivity of MgO doped with manganese in the temperature range 0.4 to 300K indicate the existence of resonant scattering by Mn 3+ ions at about 160 and 630 GHz. This cannot be accounted for by simple crystal-field theory but is consistent with the dynamic Jahn-Teller theory of Fletcher and Stevens (1969) with the parameters delta (tunnelling frequency)=480 GHz and D (spin-orbit splitting)=120 GHz. These frequencies and parameters are the same within experimental error as those determined for the isoelectronic Cr 2+ in MgO using the same technique by Challis et al. (1978).