Magnetic and optical properties of (GaMn)N nanocrystalline powders prepared by the aerosol-assisted vapour phase synthesis and anaerobic imide route methods

Herein, we report a study on magnetic and optical properties of hexagonal (GaMn)N nanocrystalline powders obtained by two methods: aerosol-assisted vapour phase synthesis and anaerobic imide route. Measurements of the magnetization as a function of temperature and magnetic field for the powders show a typical paramagnetic behaviour. In addition, antiferromagnetic contribution originating from a residual MnO by-product and a small ferromagnetic contribution are observed. Magnetization measured as the function of magnetic field shows a smaller saturation effect than expected for non-interacting Mn-ions. Electron paramagnetic resonance (EPR) measurements reveal a single, structureless resonance line with a g-factor equal to 2.008+/-0.003 indicating a presence of Mn2+-centres in the samples. Both magnetic and EPR measurements suggest weak AF interactions between Mn-ions incorporated in (GaMn)N.