On the Peculiarities of the Temperature Dependence of the Magnetoelectric Susceptibility of Chromium Oxide.

We have shown that in the chromium oxide the components of the tensor of magnetoelectric susceptibility α 33 ( T ) in the original phase and α 31 ( T ) in the spin-flop phase exhibit similar temperature dependencies. It's proved in the present paper that noted above behavior of these components can be explained in the framework of the phenomenological theory if one takes into account invariants of the third and fifth order of magnitude in the components of the antiferromagnetic vector in the phenomenological thermodynamic potential with explicitly separated exchange and relativistic terms. Also, the form of thermodynamic potentials elaborated in this paper suggests that the transition to the spin-flop phase in the chromium oxide is incomplete and α 33 cannot be equal to zero in the spin-flop phase. [ABSTRACT FROM AUTHOR]