化学共沉淀法制备MnZn铁氧体前驱物微粉及其性能

首先对Me(Me=Fe2+、Mn2+、Zn2+)在Me-NaOH-H2O体系中的沉淀行为进行了必要的热力学分析,在此基础上,通过化学共沉淀法制备了尖晶石型的MnZn铁氧体前驱物微粉。利用XRD、SEM对前驱物粉料的粒度分布、物相以及表面形貌进行了表征与测试,并结合TG-DSC(热重与差热扫描分析)对前驱物微粉的煅烧温度进行了分析。前驱物微粉的磁性能由振动样品磁强计(VSM)来表征。实验表明Me在Me-NaOH-H2O体系中共沉范围为10.0～10.7。在此pH范围内,配以一定的盐溶液流速及搅拌速度下,可直接制备出具有尖晶石结构的前驱物微粉,并有效地解决了共沉淀制粉中的洗涤困难的问题。前驱物粉的磁性能测试表明,比饱和磁化强度σs≈64.09A.m2/kg,比剩余磁化强度σr≈3.08A.m2/kg,矫顽力Hc≈0.51A/m。

Preparation and properties of MnZn ferrite precursor powders by chemical co-precipitation

According to the latest thermodynamic data,the thermodynamic analysis of different Me ions(Me=Fe2+,Mn2+,Zn2+) on the system of Me-NaOH-H2O had been carried out.Then,MnZn ferrite precursor powder was prepared by using co-precipitation.Then the precursor was studied by XRD and SEM,and the temperature of calcination is analyzed by TG-DSC.The vibrating sample magnetometer(VSM) was used to investigate the magnetic properties.It shows that the Me ions can co-precipitate in Me-NaOH-H2O system at pH value of 10.0-10.7.On this basis,the MnZn ferrite precursor powders with spinel structure were obtained directly,which can solve the difficult issue in washing process.The magnetic investigation indicates that the specific saturation magnetization σs,the retentive magnetism σr,and coercive force Hc of the precursor power are 64.09,3.08A·m2/kg and 0.51 A/m respectively.