Synthesis and Magnetic Studies of Nanocrystalline Nickel Nitride Material

Abstract

Single domain Ni 3 N nitride particles are synthesized by simultaneous decomposition and nitridation in ammonia atmosphere of [Ni(NH 3 ) 6 ](NO 3 ) 2 complex crystals at 650 K. The Ni 3 N phase crystallizes in the hexagonal structure with unit cell parameters a = 4.624(4) A and c = 4.316(4) A, 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. Ni 3 N particles exhibit a Curie temperature of T C = 634 K. In the field dependence magnetic measurements, the presence of hysteresis loop indicates ferromagnetic behavior with σ s = 1.678 emu/g, σ R = 0.50 emu/g and μ 0 H c = 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 Ni 3 N.