Magnetic properties of heavily Mn-doped quaternary alloy ferromagnetic semiconductor (InGaMn)As grown on InP

We have studied magnetic properties of heavily Mn-doped [(In0.44Ga0.56)(0.79)Mn-0.21]As thin films grown by low-temperature molecular-beam epitaxy on InP substrates. (InGaMn)As with high Mn content (21%) was obtained by decreasing the growth temperature to 190 degreesC. When the thickness of the [(In0.44Ga0.56)(0.79)Mn-0.21]As layer is equal or thinner than 10 nm, the reflection high-energy electron diffraction pattern and transmission electron microscopy show no MnAs clustering, indicating that a homogeneous single crystal was grown. Magnetic circular dicroism characterizations, as well as transport and magnetization measurements, indicate that the Curie temperature is 125-130 K. (C) 2003 American Institute of Physics.