Structural and magnetic properties of GaN/Mn nanopowders prepared by an anaerobic synthesis route†

摘要: A new oxygen-free molecular precursor system based on (i) ammonolysis in refluxing/liquid NH3 of selected mixtures gallium tris(dimethyl)amide Ga(NMe2)3 and manganese bis(trimethylsilyl)amide Mn[N(SiMe3)2]2 (Me = CH3, initial Mn-contents 0.1, 5, 20, 50 at.%) followed by (ii) pyrolysis under flowing ammonia gas at 500, 700, 900 °C afforded a range nanocrystalline powders the GaN/Mn system. The nanopowders were characterized mainly powder XRD diffraction, FT-IR spectroscopy, Raman SEM/EDX morphology examination, XRF elemental analysis. Magnetization measurements as function magnetic field temperature carried out with SQUID magnetometer. Structurally, materials shown to be single-phases nitride lattice. presence small quantities residual amorphous Mn/N/Si/C species due an incomplete transamination/removal trimethylsilylamide groups during was deduced from XRF, FT-IR, Raman, magnetization data. Magnetic properties for all consistently pointed paramagnetic GaMnN phase antiferromagnetic interactions among Mn-centers that favorable circumstances reached level 3.8 at.% Mn. accompanied facile oxidation air excessive Mn-containing by-products.