Magnetoelectric effect in the spin-flop phase of Cr2O3 and the problem of determining the magnetic structure
Belov D. V. , Vorob'ev G. P. , Kadomtseva A. M. , Popov Yu. F., Zvezdin A. K.
The magnetoelectric effect has been studied in the spin-flop phase of Cr203 in pulsed magnetic fields up to 200 kOe over the temperature range 4.2-300 K. It is shown theoretically that the coefficient cc33 in this phase is described as a function of the components of the antiferromagnetism vector by α}} = χ1 A6 Ly(L2y — ЪЬ2Х). In other words, this coefficient is relativistically small in comparison with other components of the magnetoelectric tensor. An experiment involving a careful orientation of the magnetic field with respect to the с axis of the crystal revealed a33 = 0, within the experimental error. Possible reasons for a nonzero observed value of a33 are discussed.