明胶网络凝胶法制备纳米镍锌铁氧体粉体

pH值对明胶网络凝胶法制备镍锌铁氧体纳米粉体具有决定性的作用,最佳pH值范围为9至11.加入添加剂可在较低的煅烧温度下使杂相消失并得到单相镍锌铁氧体产物.当明胶的用量由5%上升至20%(质量分数,下同)时,经700 ℃煅烧2 h后,产物晶粒由46 nm减少至10 nm,可通过改变明胶浓度的方法调控镍锌铁氧体的晶粒.镍锌铁氧体的比饱和磁化强度和矫顽力分别随粉体晶粒尺寸的增加呈先下降后上升的趋势.

Preparation of Nickel-Zine Ferrite Nano-Powder via Gelatin-Network Gel Method

The pH value was the important parameter in the preparation processing of nickel-zine ferrite nano-powder via gelatin-network gel method, and the optimum pH value was in the range of 9-11. Monophase nickel-zine ferrite without impurity phase could be obtained via adding additive after sintering at low temperature. Crystalline size of nickel-zine ferrite powder was reduced to 10 nm from 46 nm after sintered at 700 ℃ for 2 h as the gelatin concentration increasing from 5 wt% to 20 wt%. Different crystalline sizes of the nickel-zine ferrite were obtained under different gelatin concentration. The specific saturation magnetization and the coercivity of the nickel-zine ferrite first decreased and then increased with the increase of the crystalline size of the powder.