Lattice parameters of relaxed wurtzite indium nitride powder obtained by MOCVD

We have grown by metal–organic chemical vapour deposition a thick layer of indium nitride (1.4 μm) on a sapphire substrate using appropriate growth parameters. The substrate was then removed and the layer reduced to powder by a soft mechanical method. The resulting material was used to obtain an X-ray powder diffraction profile for completely relaxed indium nitride, i.e. without strain due to the lattice mismatch with sapphire. The diffraction measurement was made with a Phillips XPERT-Pro diffractometer, without slits, and collected using CuK α radiation at 300 K. The powder pattern contains many ( h k l ) peaks, depending upon two lattice parameters, a and c , for the wurtzite crystal structure. A two-dimensional least squares procedure was adapted to minimize the fitting errors on the experimental data. The lattice parameters were accurately extracted and will be given here.