The Preparation of Magnetic Ni-Ferrite Particles with Specific Shape

• Main Authors: Yun-Kuan Chen, 陳耘寬
• Other Authors: Yen-Hwei Chang
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/35256420959610397833

碩士 === 國立成功大學 === 材料科學及工程學系 === 89 === Nickel ferrite is prepared by conventional solid-state sintering process. The crystal with cubic shape made by further reaction in the molten salt was expected. In this investigation, crystal with particular plane is not be etched by the appearance of salt but liquid-phase growth. Crystal shape can be controlled by liquid-phase diffusion. For Na2CO3 flux, the equilibrium crystal shape is octahedron with constituent of eight {111} planes, (grain size)1 is in proportion to time. The octahedral Ni-ferrite particles around 70μm has been prepared by annealing at 1000℃ for 4hr. For KCl flux, it is difficult to obtain a specific grain, but equiaxied particles. A large area of {100} planes by annealing 2hr at 950℃, and of {110} planes in 1050℃ were found. Unfortunately, a cubic shaped magnetic particle formed with {100} planes can still not be prepared.