Influence of additives on the properties of spherical nickel particles prepared by ultrasonic spray pyrolysis

Abstract

Ideal spherical nonagglomerated Ni particles (mean diameter 0.62-1.12 m) were prepared by ultrasonic spray pyrolysis of NiCl 2 aqueous solution in the presence of 0.1 mass% of Pd, Cu, or Ni in an H 2 -N 2 atmosphere at 900°C. Incomplete reduction of the NiCl 2 aqueous solution in the absence of additives was observed under the same conditions. Differential thermal and thermal-gravimetric analyses revealed a decrease in initial reduction temperature of NiCl 2 from 375 to 275°C by the addition of Pd, Cu, or Ni. The morphology of Ni particles was analyzed using scanning tunneling microscopy. The surface roughness of Ni particles was found to be controllable by addition of appropriate additives.

Phase transition from the ferromagnetic to superparamagnetic with a loop shift in 5-nm nickel particles

“…Nickel nanoparticles have been confirmed experimentally using several different techniques: ultrasound irradiation [14], evaporation technique [15], ultrasonic spray pyrolysis [16], chemical reduction [17], electrochemical technique [18], and polyol method [19]. In the current study, the microwave-assisted polyol method is used to obtain monodispersed nickel particles with 5-nm diameters.…”

Preparation of mono-disperse Ni powders via the reduction of hydrazine complexes: The effect of source materials and impurities

“…When a 50% NaOH solution was added, the solution color changed from a short to long wave length (from pale violet via blue to green), which indicates a decrease in the concentration of NH 3 or N 2 H 4 radicals in the Ni-complex [4]. This suggests that the supply of OH − promotes the decomposition of a Ni-complex.…”

“…The Ni powder for MLCC can be prepared via vapor phase methods [3], spray pyrolysis [4,5], solution chemical routes such as the polyol process [6,7], and reduction in an emulsion [8], aqueous [9][10][11][12] and non-aqueous solutions [13]. Among the various routes for Ni powder synthesis, the reduction in the solution is a cost-effective and promising approach for preparing crystalline and spherical Ni powders.…”

Synthesis conditions in tailoring morphology of reticular particles in porous nickel powders prepared by template-assisted polyol process

“…[6][7][8][9][10]. Among these methods, the chemical solution process is a costeffective and promising approach for large-scale production and control of structure and morphology of the particles [11,12].…”