Synthesis and characterization of ɛ-Fe3N/GaN, 54/46-composite nanowires

ɛ-Fe3N/GaN, 54/46-composite nanowires (aspect ratio: 40), with core–shell structure, are synthesized by wet chemical method. Structural and morphological investigations are performed using X-ray diffraction (XRD)-Rietveld analysis and microscopy techniques. The encapsulation of ɛ-Fe3N by GaN is probed by X-ray photoelectron spectroscopy (XPS). The in-depth profile analysis probes the large interface region consisting both the phases. Although the respective surface oxynitride phases are present, the nitride phases are dominant inside the nanowires. The interface region of the nanowires influences the low temperature magnetic behavior. The superparamagnetic and ferromagnetic fractions coexist even at 5 K, due to the nanowire size distribution. Spin-glass-like collective ordering is observed below 50 K due to the freezing of the localized frustrated spins. Room temperature photoluminescence (PL) reveals the presence of surface states in the GaN shell.