Synthesis and Magnetic Studies of Nanocrystalline Nickel Nitride Material

Single domain Ni3N nitride particles are synthesized by simultaneous decomposition and nitridation in ammonia atmosphere of [Ni(NH3)6](NO3)2 complex crystals at 650 K. The Ni3N phase crystallizes in the hexagonal structure with unit cell parameters a = 4.624(4) Å and c = 4.316(4) Å, and has a crystallite size of 16 nm. In TEM study, these nanosize particles show spherical shape, and form particle aggregates of 18 nm size. Ni3N particles exhibit a Curie temperature of TC = 634 K. In the field dependence magnetic measurements, the presence of hysteresis loop indicates ferromagnetic behavior with σs = 1.678 emu/g, σR = 0.50 emu/g and μ0Hc = 0.022 T. In this phase, the density of states (DOS) of Ni is dominated by 3d states and is mixed with 2p DOS of N. The contribution of d-electrons in the intra-band polarization affects the magnetic moment of Ni and thus the magnetic moment of Ni3N.