La3＋掺杂 Ni0．35 Co0．15 Zn0．5 Fe2 O4铁氧体的制备及微波吸收性能

采用溶胶-凝胶自蔓延法制备 La3＋掺杂 Ni0．35 Co0．15 Zn0．5 Fe2 O4，并研究不同掺杂量对样品微观结构、电磁参数及微波吸收性能的影响。通过 X 射线衍射仪、扫描电镜研究了样品的相结构和微观形貌，使用振动样品磁强计与矢量网络分析仪分别对样品的静态磁性能及在1～12GHz 的电磁参数进行了研究，并计算了不同厚度（3 mm、5 mm、8 mm）下材料的反射损耗。研究表明，适量掺杂 La3＋能够提高 Ni0．35 Co0．15 Zn0．5 Fe2 O4铁氧体的吸波性能，并使吸收频带向高频移动。其中样品 Ni0．35 Co0．15 Zn0．5 La0．04 Fe2 O4与石蜡混合厚度为5mm 时，最小反射损耗为－28．4dB，小于－10dB 带宽为3．7GHz。

Preparation and Microwave Absorbing Properties of La3 + Doped Ni0.35 Co0.15 Zn0.5 Fe2 O4 Ferrites

La3 + doped NiCoZn-ferrite particles were prepared by the sol-gel method,the influence of La3 + content on microstructure, electromagnetic parameters and microwave absorbing properties was studied.Phase structure and microscope image of the sample were investigated by X-ray diffraction and scanning electron microscopy,their static magnetic properties and electromagnetic parameters at 1-12GHz were measured by a vibrating sample magnetometer and vector network analyzer respectively,and the reflection loss was cal-culated with different thicknesses(3mm,5mm,8mm).The results show that doping appropriate amount of La3 + can enhance the mi-crowave absorption of Ni0.35 Co0.15 Zn0.5 Fe2 O4 -ferrite,and remove the absorbing band to high frequency.When the sample thickness of Ni0.35 Co0.15 Zn0.5 La0.04 Fe2 O4 mixed with paraffin is 5mm,the minimum reflection loss is -28.4dB,bandwidth (RL≤ -10 dB)is 3.7GHz.