Epitaxial δ-MnxGa1-x layers on GaN(0001): Structural, magnetic, and electrical transport properties

Structural, magnetic, and electrical transport properties of delta-MnxGa1-x epitaxial layers are investigated for alloy compositions in the range of x = 0.49 ... 0.67. All samples were grown by molecular beam epitaxy on GaN(0001) layers and exhibit a high-quality interface. The room-temperature saturation magnetization and the coercive field change markedly with alloy composition. An analysis of the electrical transport properties reveals that the lattice and magnon scattering contributions to the longitudinal resistivity as well as the scaling behavior of rho(AHE) also depend noticeably on the composition of the delta-MnGa layer. The possibility to grow delta-MnGa epitaxially on GaN(0001) over a wide range of Mn compositions and a detailed knowledge of the related physical properties are a prerequisite for the integration of this ferromagnetic alloy in wide-gap semiconductor spintronics.