Wet Preparation of Organic-Stabilizer-Free Urchin Structured Nickel Fine Particles and Their In Situ TEM Observation at High Temperatures

Urchin structured nickel fine particles were successfully obtained by the hydrazine reduction of NiCl2·6H2O in ethanol. The particle structures, particularly the aspect ratios of the nickel nanoneedles on the surface, were controlled by changing the sequence of the addition of hydrazine and sodium hydroxide. These particles were not stabilized by organic compounds. In situ TEM observations at high temperatures revealed that the obtained fine particles began to deform at 350°C. [doi:10.2320/matertrans.M2014176]