氧化-共沉淀法制备Mn-Zn铁氧体的机理及影响因素

以FeSO4.7H2O、MnSO4.H2O、ZnSO4.7H2O、HCl为原料,NaOH溶液为沉淀剂、H2O2为氧化剂,采用氧化-共沉淀法在液相中制备Mn-Zn铁氧体,通过傅里叶变换红外光谱仪(IR),X射线衍射仪(XRD)和振动样品磁强计(VSM)对样品进行表征,讨论了Mn-Zn铁氧体在液相中的形成机理和氧化共沉淀法制备Mn-Zn铁氧体的影响因素。结果表明:采用氧化-共沉淀法能在液相中直接制备出Mn-Zn铁氧体,溶液的浓度和pH值是形成单相Mn-Zn铁氧体的两个关键因素;溶液的浓度和pH值低时,制备出的样品中含有非晶相FeOOH且饱和磁化强度低。     

A simple solution route to control synthesis of Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> nanomaterials at low temperature and their magnetic properties

A series of nanostructured iron compounds including cubic Fe₃O₄ and orthorhombic FeOOH were synthesized via a facile low temperature (in the range of 60?100°C) solution method. In the whole process, the interaction between FeCl₂·4H₂O and methenamine (C₆H₁₂N₄) was carried out through a reflux device under different reaction conditions such as temperature, solvent, and duration. The samples were detected by XRD, TEM, SAED, physical property measurement system, and Mössbauer spectroscopy, separately. The experiments showed that magnetic mixture nanoparticles had flake and rod morphologies, and cubic Fe₃O₄ took on grain nanostructure. Magnetism measurements indicated that the saturated magnetization of the as-obtained magnetic mixture was lower than that of the cubic magnetite. Mössbauer spectroscopy testified the sample consisting of cubic magnetite rather than γ-Fe₂O₃. In addition, a possible growth mechanism of cubic magnetic nanoparticles under different conditions was discussed.