低热固相反应制备Ni_(0．6)Cu_(0．2) Zn_(0．2) Fe_2 O_4纳米晶铁氧体

Synthesis of Ni_0.6 Cu_0.2 Zn_0.2 Fe_2O_4 via Solid State Reaction at Low Heating Temperatures

用低热固相反应合成了纳米Ni_(0．6)Cu_(0．2)Zn_(0．2)Fe_2O_4尖晶石型铁氧体,并应用FT-IR、DTA-TG、XRD、TEM以及SEM等测试技术对低热固相反应过程和样品进行了研究。FT-IR分析表明,将摩尔比为1:1的金属硝酸盐与柠檬酸研磨30 min能够发生低热固相反应,生成具有单齿配位的金属柠檬酸配合物;当形成于凝胶后．金属与柠檬酸的配合物具有单齿和桥式2种结构;干凝胶在不同焙烧温度下产物的FT-IR和XRD分析结果表明．随着焙烧温度升高,尖晶石结构逐渐发育完整;依据谢乐公式计算和TEM表征证明,干凝胶在350℃分解1 h后的粒径为30～40 nm,将此粉体在900℃下焙烧2 h后,粒径增大到200～300 nm。

Ultrafine powder of spinel type ferrite Ni0.6Cu0.2Zn0.2Fe2O4 was prepared from Fe（ NO3 ）3 · 9H2O, Ni（ NO3 ） 2 · 6H2O, Zn （ NO3 ） 2 · 6H2 O, Cu （ NO3 ） 2 · 3H2O and citric acid via solid state reaction at low heating temperatures. The reaction mechanism and structure of the product were investigated by means of FT-IR, DTA-TG, XRD, TEM and SEM. The FT-IR results show that the metal ions could react with citric acid by grinding for 30 min, and the carboxyl groups of the citric acid were coordinated to the metal ions in a monodentate fashion. The XRD and FT-IR analyses for the samples sintered at different temperatures indicate that the spinel crystal structure integrates gradually with the increase of the calcination temperature. According to the calculation via the Scherrer formula and the TEM analysis, the particle size of the ferrite was about 30 -40 nm after the dried gel was decomposed at 350 ℃ for 1 h, and the particle size increased to 200 - 300 nm when the decomposed dried gel sample was sintered at 900 ℃ for 2 h.