TO THE PROBLEM OF TRIANGLE ANTIFERROMAGNETIC ORDERING STABILITY IN A RHOMBOHEDRAL LATTICE OF BETA-OXYGEN

The stability of triangle antiferromagnetic ordering in a rhombohedral lattice of beta-oxygen in relation to the formation of an inhomogeneous superstructure is considered in terms of the average field theory. The occurrence of a long-period modulation is shown to result in a decrease of the ground state energy. Contrary to the previous investigations, the authors apply, as a zero approximation, an antiferromagnetic ordering with alternating polarity of neighbouring X-Y layers which seems to be true for beta-oxygen.