Effect of electron-beam irradiation on the magnetic properties of Ga1−xMnxAs thin films grown on GaAs (100) substrates

The effect of electron-beam irradiation on the magnetic properties of (Ga1−xMnx)As thin films grown on GaAs (100) substrates by using molecular beam epitaxy was investigated. The ferromagnetic transition temperature (Tc) of the annealed (Ga0.933Mn0.067)As thin films was 160 K. The Tc value for the as-grown (Ga0.933Mn0.067)As thin films drastically decreased with increasing electron-beam current. This significant decrease in the Tc value due to electron-beam irradiation originated from the transformation of Mn substituted atoms, which contributed to the ferromagnetism, into Mn interstitials or Mn-related clusters. These results indicate that the magnetic properties of (Ga1−xMnx)As thin films grown on GaAs (100) substrates are significantly affected by electron-beam irradiation.