Shape evolution of NiS2 minicrystals via thermodynamic controlled growth

✍ Scribed by Xiao-Feng Zhou; Lin Lin; Wei Wang; Sheng-Yue Wang

• Book ID: 104022199
• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 430 KB
• Volume: 314
• Category: Article
• ISSN: 0022-0248
• DOI: 10.1016/j.jcrysgro.2010.11.055

✦ Synopsis

Large-scale NiS 2 minicrystals with size of 5-10 mm were synthesized by ultrasonic spray pyrolysis technique. The shape of the obtained NiS 2 minicrystals ranges from tetrahedron to cone. It was found that these two shape formations of tetrahedral and conical NiS 2 minicrystals were temperature-dependent, i.e., with temperature increasing, such as high to 743 K, it would result in the formation changing from tetrahedron to cone. It indicates that the nucleation probability of tetrahedral structure is larger than that of conical structure. The nucleation thermodynamics and growth mechanism were proposed to elucidate the temperature-dependent shape evolution. The theoretical predications are in good agreement with experimental results, suggesting that the thermodynamic driving force and the Gibbs free energy difference between two phases are the physical origin of the shape evolution.