In the framework of the symmetry theory the phase diagram of an easy-plane quasi 1D hexagonal antiferromegnet is studied. The splitting of the transition into two transitions of second order is shown to occur near the Neel temperature of 3D ordering. The degree of splitting depends on the field direction. Ordering is found to occur via an intermediate collinear phase. In the field-exchange approximation there exists a strongly nonlinear transverse magnetization in the spiral phase.
|Number of pages||11|
|Journal||Journal of Experimental and Theoretical Physics|
|Publication status||Published - Apr 1993|