Tailoring magnetism of multifunctional MnxGa films with giant perpendicular anisotropy

We report wide-range composition and annealing effects on magnetic properties of MnxGa films grown on GaAs (001) by molecular-beam epitaxy. We obtained single-crystalline MnxGa films in a surprisingly wide composition range from x = 0.76 to 2.6. We show that the magnetism could be effectively tailored by adjusting composition and annealing. Especially, when 0.76 <= x <= 1.75, MnxGa films simultaneously show magnetization from 130 to 450 emu/cc, perpendicular anisotropy from 8.6 to 21 Merg/cc, intrinsic coercivity from 4.38 to 20.1 kOe, normal coercivity to 3.6 kOe, energy product up to 3.4 MGOe, and thermal-stability up to at least 350 degrees C in contact with GaAs. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4799344]