In-Plane Magnetic Anisotropy and Temperature Dependence of Switching Field in (Ga, Mn)As Ferromagnetic Semiconductors

In English We explore the magnetic anisotropy of GaMnAs ferromagnetic semiconductor by Planar Hall Effect (PHE) measurements. Using low magnitude of applied magnetic field (i.e., when the magnitude H
is smaller than both cubic Hc and uniaxial Hu anisotropy field), we have observed various shapes of applied magnetic field direction dependence of Planar Hall Resistance (PHR). In particular, in two
regions of temperature. At T TC/2 the “zigzag-shape” signal of PHR. They reflect different magnetic anisotropy and provide information about magnetization
reversal process in GaMnAs ferromagnetic semiconductor. The theoretical model calculation of PHR based on the free energy density reproduces well the experimental data. We report also the temperature dependence of anisotropy constants and magnetization orientations. The transition of easy axis from biaxial to uniaxiale axes has been observed and confirmed by SQUID measurements.