Peculiarities of Jahn-Teller phase transitions in mechanically activated perovskite- structured oxides

The model which considered the influence of the final grain size on the the Jahn-Teller type structural phase transitions  in non-stoichiometric oxides with the perovskite structure has been proposed. The  microscopic description of  the cooperative Jahn-Teller effect  was suggested for the effects caused by mechanic activation of oxide systems up to nano sizes. The grain size decrease is shown to proceed along with abundant oxidation (as related to the coarse grain samples). The theoretical assumptions were found to correspond qualitatively with experimental data on the phase state of the mechanically activated NdMnO3+δ oxide.


  1. A. Fishman, N. Tkachev. Jahn-Teller Phase Transitions in Non-Stoichiometric Oxides with Perovskite Structure: Effect of Mechanical Activation, Defect and Diffusion Forum, Vols. 334-335, 2013,  pp 353-358.
  2. L.B. Vedmid, V.B. Vykhodec, Yu.V. Golikov, T.Ye. Kurennykh, L.I. Leontiev, N.K. Tkachev, O.M.Fedorova, A.V. Fetisov, A.Ya. Fishman, A.M. Yankin. Properties of mechanically activated NdMnO3+δ oxide. Reports of the Academy of Sciences. Physical Chemistry, Volume 445, № 3, 2012, pp. 292-295.

Author:  Tkachev N.K., DSc (Chemistry)