Molecular field anisotropy

While the molecular field tends to stabilize sublattices with symmetries [Fig. 10c, Eq. (24c)], the anisotropy contributions from the nonlinear Jahn-Teller coupling shift the sublattices towards the positions with tetragonal symmetry [Fig. 10a, Eq. (24b)]. Depending on the ratio of molecular field strength and anisotropy energy situations between the extremes (Fig. 10b) may be stabilized, as already discussed. If one approaches the phase transition, dynamic contributions become of... 

Anisotropic contributions to the exchange may be included in the single-ion anisotropy, within the molecular field approximation. Since the hep structure contains two atoms per unit cell, 5ifex may be described in terms of exchange interactions between magnetic ions on the same and different sublattices, respectively (R) and S iR)... 

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