Calculation of phase transition characteristics of magnetically ordered system by renormalization group method
The phase transition - > of magnetic moments of sublattices in segnetoantiferromagnetics in the strong magnetic field is under consideration. It is shown, that spin fluctuations play an essential role and determine characteristics of the phase transition. The consecutive account of spin fluctuations by renormalization group method and $\eps$-expansion leads to the result that the phase transition in segnetoantiferromagnetics in the strong magnetic field occurs to be phase transition of the first order close to the second one.