Average and Local Crystal Structures of (Ga1–xZnx)(N1–xOx) Solid Solution Nanoparticles

Abstract

We report the comprehensive study of the crystal structure of (Ga1􀀀xZnx)(N1􀀀xOx) solid solution nanoparticles by means of neutron and synchrotron x-ray scattering. In our study we used four different types of (Ga1􀀀xZnx)(N1􀀀xOx) nanoparticles, with diameters of 10 - 27 nm and x = 0.075 - 0.51, which show the narrow energy-band gaps from 2.21 to 2.61 eV. The Rietveld analysis of the neutron diffraction data revealed that the average crystal structure is the hexagonal wurtzite (space group P63mc), in agreement with previous reports on similar bulk materials. The pair-distribution function (PDF) analysis of the same data found that the local structure is more disordered than the average one. It is best described by the model with a lower symmetry space group P1, where atoms are qusirandomly distorted from their nominal positions in the hexagonal wurtzite lattice.