Ni74Mn20Ga6 alloys grown by molecular beam epitaxy on GaAs/AlAs/In0.2Ga0.8As (001)

We report the fabrication of Ni74Mn20Ga6 alloys on GaAs/AlAs/InGaAs (001) substrates with a native oxide layer by molecular beam epitaxy. The structure and magnetic properties of the alloys are investigated by electron microscopy, x-ray techniques, and magnetization measurements. Relatively smooth films with a granular morphology and a tetragonal structure with ratio c/a = 2.05 (film) are obtained. The alloy shows ferromagnetic behavior at room temperature and the Curie temperature is identified at 320 K. In addition, strong magnetic anisotropy due to strain is observed at low temperatures. The experimental hysteresis curves are compared with micromagnetic simulations. Finally, the roll-up of InGaAs/Ni74Mn20Ga6 bilayers is demonstrated.