镧系元素掺杂Mn-Zn铁氧体的制备和研究

Preparation and Characterization of Nanosize Lanthanide Doped Mn-Zn Ferrite

本文以Fe2(SO4)3、ZnSO4·7H2O、MnSO4·H2O和Ln(NO3)3(Ln=La、Ce、Nd)为原料,通过水热合成法制备出了镧系元素(Ln=La、Ce、Nd)掺杂Mn鄄Zn铁氧体(Mn0.6Zn0.4LnxFe2-xO4)超细粉末,并利用XRD、TEM和VSM等手段对样品进行了表征,讨论了Ln掺杂量与掺杂种类对Mn鄄Zn铁氧体样品的影响。结果表明:要得到单相尖晶石型Mn0.6Zn0.4LnxFe2-xO4,Ln掺杂量(x)应小于0.1;适量Ln的掺杂可以大大改善Mn鄄Zn铁氧体的磁性能。

Nanosize lanthanide doped manganese zinc ferrites were prepared by hydrothermal precipitation route using Fe-2(SO4)(3), ZnSO4.7H(2)O, MnSO4.H2O and Ln(NO3)(3) (Ln=La, Ce, Nd) as raw materials, and characterized by XRD, TEM and VSM., The results of XRD and TEM showed that lanthanide doping amount should not exceed 0.1 to maintain Mn-Zn ferrites' regular cubic spinel crystal structure and their good magnetic properties. The particles for Mn-Zn ferrites doped with different lanthanide elements were all uniformly sized nanoparticles with little aggregation and their sizes decreased in the order of La3+, Ce3+ and Nd3+. The VSM studies indicated that saturation magnetization (B.) of lanthanide doped Mn-Zn ferrite was obviously greater than that of pure Mn-Zn ferrite, and its values increased in the order of La3+, Ce3+ and Nd3+, which is consistent with their 4f electrons' numbers (4f(0), 4f(1) and 4f(3), respectively). The changing trends with lanthanide content (x) of saturation magnetization (B-S) and coercitivity (H-C) of La3+, Ce3+ and Nd3+ doped Mn-Zn ferrites were different when x was less than 0.1, which might be due to the influences of the substitution of Fe3+ on the magnetic superexchange interactions between octahedral B sites and tetrahedral A sites. On the other hand, when x was larger than 0.1, their changing trends were similar to each other.