Mn0.8Zn0.2Fe2O4/MgAl-LDHs复合材料的磁性能和磁热效应

采用共沉淀法将纳米锰锌铁氧体粒子(Mn_0.8Zn_0.2Fe₂O₄)与镁铝双金属氢氧化物(MgAl-LDHs)进行组装合成了磁性纳米镁铝双金属氢氧化物, 并通过TEM、FTIR、DTA、XRD、VSM等方法对其进行表征. 样品的结构分析结果表明, 复合材料具有典型的核壳结构, 镁铝双金属氢氧化物被赋予磁性后并没有改变其层状结构的典型特征. 样品的磁学性能和磁热性能测试结果表明, 铁氧体的含量对复合材料的磁性能和磁热效应起着决定性作用; MgAl-LDHs对铁氧体粒子没有显著的磁屏蔽效应, 复合材料的饱和磁化强度与铁氧体的含量呈正线性相关, 而复合材料的矫顽力随MgAl-LDHs含量的增加呈现先减小后增大的趋势, 但整体变化幅度很小, 同时MgAl-LDHs对铁氧体粒子磁热效应的影响也极小.

Magnetic Properties and Thermomagnetic Effect in Mn0.8Zn0.2Fe2O4/MgAl-LDHs Composite

A magnetic layered inorganic-inorganic composite involving manganese zinc ferrite (Mn_0.8Zn_0.2Fe₂O₄) and Mg-Al layered double hydroxides (MgAl-LDHs) was assembled by coprecipitation method. The products were characterized by TEM, FTIR, DTA, XRD and VSM. The results indicate that the composite has core-shell structure, the introduction of ferrite particles does not change the typical layered-structure of MgAl-LDHs phase. MgAl-LDHs has infinitely small magnetic shielding effect on ferrite particles, the saturation magnetization values of the composite increase linearly with the ferrite content, however, is the MgAl-LDHs content increasing, the ceorcivity values of the composite decrease first, then increase subsequently, but these changes are small on the whole. In addition, the LDHs layer also has infinitely small effect on the thermomagnetic effect of ferrite particles. It is obvious that the ferrite content in the composite plays a decisive role on magnetic properties and thermomagnetic effect.