Nepochatykh Y. THE ROLE OF THE LONGITUDINAL OSCILLATIONS OF MAGNETIZATION IN DYNAMICS OF THE ORIENTATIONAL TRANSITIONS

An experimental investigation of the resonance properties of orthoferrites of erbium and samarium and iron borate at points of different orientational phase transitions has been performed. The contribution of longitudinal oscillation of magnetization in the energy gap value of the soft magnetic-resonant mode in small magnetic fields are discovered. It is shown that contributions to the dynamic from precession and longitudinal oscillation of magnetization are additive and competing ones.Dependence of contribution of longitudinal oscillation of magnetization from incorporated parameter that characterize the magnetic material - relations of temperature of reorientation to the Neel temperature is determined. Jump of soft mode frequencies in iron borate in the point spontaneous orientational transition has been experimental discovered. This jump is explained by the contribution of dipole interaction into the expression for the soft quaziferromagnetic mode.