Molecular beam epitaxy of wurtzite GaN-based magnetic alloy semiconductors

The preparation of hexagonal GaN:Mn and GaN:Fe epilayers has been studied b y RF-plasma-assisted molecular beam epitaxy. GaN:Fe epilayers exhibit super paramagnetic behavior, presumably due to ferromagnetic inclusions. GaN:Nln epilayers can be expressed in the form of Ga1-xMnxN with x up to 0.02, indi cating the successful preparation of the GaN-based magnetic alloy semicondu ctor for the first time. The epilayers are primarily paramagnetic and highl y resistive. For epilayers with very high Mn concentration (similar to 10(2 1) cm(-3)), analysis of the paramagnetic component has revealed the effecti ve spin number S approximate to 2.5 together with the positive paramagnetic Curie temperature. This suggests the presence of ferromagnetic spin exchan ge between Mn ions.