Spherical shape Ni–Co alloy powders directly prepared by spray pyrolysis

• Published in: Journal of alloys and compounds 2009-06, Vol.478 (1), p.206-209
• Main Authors: Jang, Hee Chan, Ju, Seo Hee, Kang, Yun Chan
• Format: Article
• Language: English
• Subjects: Ceramics; Chemical synthesis; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Gas–solid reaction; Magnetic properties and materials; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Physics; Small particles and nanoscale materials; Structure of solids and liquids; crystallography; Studies of specific magnetic materials
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2008.11.108

Spherical shape Ni–Co alloy powders were directly prepared by spray pyrolysis in reduction atmosphere. The alloy powders prepared at temperatures of 1000 and 1200 °C had hollow structures and large sizes. On the other hand, the alloy powders prepared at a temperature of 1400 °C had dense structure and fine size. The mean size and geometric standard deviation of the powders prepared at a temperature of 1400 °C were 0.69 μm and 1.5. The BET surface area of the alloy powders prepared at a temperature of 1400 °C was 1.6 m 2/g. The composition ratio of Ni and Co components were well coincided with that of the spray solution. The alloy powders had similar saturation magnetization ( M s ) values irrespective of the preparation temperatures. However, the coercive force ( H c ) values of the alloy powders decreased with increasing the preparation temperatures.