Systematic and consistent ferromagnetism in InMnP:Zn bilayers for various Mn concentrations and annealing temperatures

The p-type InP:Zn epilayers were prepared by using metal-organic chemical vapor deposition, and Mn was subsequently deposited onto the epilayer by using molecular beam epitaxy. The p-type InMnP:Zn epilayers were annealed at relatively low temperatures of 200-350 °C and contained no secondary phases such as InMn, MnP, and MnO₂, as verified by x-ray diffraction. However, minute presence of MnO₂ was confirmed using transmission electron microscopy, which agreed with the magnetic properties measured by using a superconducting quantum interference device (SQUID). From the SQUID measurements, consistent and systematic ferromagnetic properties with clear ferromagnetic hysteresis loops were observed. The Curie temperature, T _C, which persisted up to ∼ 180 K, was recorded depending on the Mn concentrations and annealing temperature. These results indicate that the ferromagnetic semiconductor InMnP:Zn can be fabricated at a very low annealing temperature without forming ferromagnetic precipitates except for MnO₂.