Magnetic anisotropy of semiconductor (Ge,Mn)Te microstructures produced by laser and electron beam induced crystallization

Ferromagnetic transition and magnetic anisotropy was studied by SQUID magnetometry and ferromagnetic resonance (FMR) methods in poly crystalline Ge 1-x Mn x Te (x = 0.085) semiconductor microstructures embedded in an amorphous, insulating, and paramagnetic (Ge,Mn)Te matrix. The microstructures were produced by pulsed laser and electron beam induced local re-crystallization of amorphous layers deposited on insulating BaF 2 substrates. The angular dependence of the FMR resonance field observed below the Curie temperature T C = 70 K of the microstructures is quantitatively described by the analysis of Zeeman and demagnetization contributions to magnetic free energy. Good agreement with experimental results obtained in the case of structures produced by pulsed laser re-crystallization indicates the formation of ferromagnetic (Ge,Mn)Te thin disks of submicron dimensions.