Micromagnetic Structures near a Second Order Phase Transition in Monocrystalline Ferrite Garnet Plates

L.A. Pamyatnykh, I.E. Belskii and G.A. Shmatov Ural Federal University, Lenin Av. 51, Yekaterinburg, 620083, Russia

Full Text PDF

The main parameters of micromagnetic structure formation in a vicinity of a second order phase transition were determined experimentally and theoretically. The theoretical study was performed using micromagnetic approach. External magnetic field Hc of appearance of micromagnetic structure and micromagnetic structure period Lc were determined for (001)-oriented plate with uniaxial Ku and cubic K1 magnetic anisotropy. The plate was saturated by the field applied in its plane. In the model we assumed that magnetization vector undergoes small deviations from equilibrium if magnetic field is slightly reduced. These deviations are periodic in nature: micromagnetic structure has a form: of a plane wave. Dependences of Hc and Lc on an azimuthal angle of external magnetic field and on anisotropy constants Ku and K1 were derived analytically in this work. Experimental studies of micromagnetic structure near the second order phase transition were conducted on (EuEr)3(FeGa)5O12 (001)-oriented 50 μm thick ferrite-garnet plate with Ku = 5700 erg/cm3 and K1=-3700 erg/cm3. Micromagnetic structure was revealed by means of magnetooptic Faraday effect. The in-plane field was increased up to 2000 Oe. Experimentally determined values of Hc and Lc were compared with theoretical estimates.

DOI: 10.12693/APhysPolA.127.421 PACS numbers: 75.60.Ch, 75.30.Kz, 75.60.Jk