稀土Gd3+掺杂对钴铁氧体结构与吸波性能的影响

Structure and Microwave absorption properties of rare earth Gd3+doped Cobalt ferrite

摘要:

本研究以十六烷基三甲基溴化铵（CTAB）为表面活性剂，C4H6CoO4·6H2O和FeCl3·6H2O为原料，晶化温度180 ℃，晶化时间8 h，在pH=11的条件下采用水热法制备钴铁氧体纳米颗粒。通过添加Gd3+研究了稀土元素及掺杂量对纳米钴铁氧体微观结构与吸波性能的影响。利用X射线衍射仪（XRD）、红外光谱（FT-IR）、透射电镜（TEM）和矢量网络分析仪（VNA）对制备的复合钴铁氧体结构性能进行表征。研究结果表明稀土元素Gd3+会对钴铁氧体的晶粒尺寸、形貌和吸波性能产生较大影响。当稀土元素掺杂量x ≤ 0.1时，复合钴铁氧体晶粒尺寸随着掺杂量增加在逐渐减小，晶格常数逐渐增加，颗粒的形状形状变为不规则四边形。当稀土元素Gd3+的掺杂量为0.025时，所制备的钴铁氧体吸波反射率达到最小，达到-14.9 dB。

Abstract:

In this thesis, cetyltrimethylammonium bromide (CTAB) was used as surfactant. C4H6CoO4·6H2O and FeCl3·6H2O were used as raw materials. The crystallization temperature was 180 ℃, the crystallization time would last 8 h and the solution was passed at pH=11. Cobalt ferrite nanoparticles were prepared by hydrothermal method. The doped rare earth elements Gd3+ was used to control the structure and absorbing properties of cobalt ferrite, and at the same time explore the optimal doping amount of rare earth elements. The structure and absorbing properties of cobalt ferrite were characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR), transmission electron microscopy (TEM) and vector network analyzer (VNA). It was found that during cobalt ferrite preparation, the doping of rare earth elements Gd3+ would have a great influence on grain size, morphology and absorbing properties. The results showed that when the doping amount of rare earth elements was x ≤ 0.1, the decrease of the grain size of cobalt ferrite and increases of the lattice constant gradually with the increase of doping amount, indicating that rare earth elements can make the particles smaller. The absorbing reflectivity of cobalt ferrite reached the minimum values of -14.9 dB when the doping amount of rare earth elements Gd3+ was 0.025.