(第二炮兵工程大學(xué) 603教研室，西安 710025)
摘 要: 在同等實驗條件下，以鎳鐵氧體為基體，通過溶膠?凝膠法，制備二元鎳基復(fù)合鐵氧體Ni0.5A0.5Fe2O4(A= Zn, Co, Mn, Cu)。用X射線衍射儀、掃描電子顯微鏡、振動樣品磁強計和矢量網(wǎng)絡(luò)分析儀對粉末的結(jié)構(gòu)及電磁性能進行表征并對其吸波性能進行優(yōu)化設(shè)計。結(jié)果表明：4種離子取代后均能形成在室溫條件下具有超順磁性的純凈鎳基鐵氧體粉末。離子取代使鐵氧體樣品的復(fù)介電常數(shù)實部ε′增大，虛部ε″在2~6 GHz和13~18 GHz變小，在6~13 GHz增大。Zn2+、Mn2+、Cu2+ 3種離子取代樣品與未進行離子取代的NiFe2O4相比，其復(fù)磁導(dǎo)率實部μ′變化不大，而Co2+離子取代樣品的μ′整體要大于其他幾種離子取代樣品及未取代樣品的μ′；在2~11 GHz進行Zn2+、Co2+、Mn2+3種離子取代樣品的虛部μ″變大，且以Ni0.5Zn0.5Fe2O4的最大，Cu2+取代樣品的虛部μ″與未取代樣品的虛部μ″相比變化不大。利用傳輸線理論優(yōu)化設(shè)計時發(fā)現(xiàn)，Co2+取代后的復(fù)合鐵氧體沒有匹配點，Zn2+取代后的復(fù)合鐵氧體匹配效果最好，在最佳匹配厚度為5.63 mm時，其最小反射率峰值為?36.26 dB，小于?10 dB的頻寬可達4.7 GHz。
關(guān)鍵字: 鎳基鐵氧體；溶膠凝膠法；離子取代；磁性能；優(yōu)化設(shè)計
（No. 603 Faculty, Xi’an Research Institute of High Technology, Xi’an 710025, China）
Abstract:The binary nickel composite ferrites Ni0.5A0.5Fe2O4 (A=Zn, Co, Mn, Cu) were prepared under the same condition via sol–gel method. The powder structure and electromagnetic properties were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and vector network analyzer, and its absorbing coating was optimized. The results show that the replacement of four kinds of ions can form pure nickel ferrite powders with super paramagnetic at room temperature. After the ions replacement, the real part ε′ of complex permittivity of the ferrite samples increases, and the imaginary part ε″ of complex permittivity of the ferrite samples decreases in 2?6 GHz and 13?18 GHz while increases in 6?13 GHz. The real part μ′ of complex permeability of the samples replaced by Zn2+, Mn2+ or Cu2+ has little change compare with that of NiFe2O4, while μ′ of the sample replaced by Co2+ is greater than those of other samples whether being replaced or not; the imaginary part μ″ of the samples replaced by Zn2+, Co2+ or Mn2+ becomes larger in 2?11 GHz, and that of Ni0.5Zn0.5Fe2O4 is the largest one, that of the sample replaced by Cu2+ has little change compared with that of the sample before replacement. It is found by the design of coating optimization that the composite ferrite replaced by Co2+ has no match point, and the composite ferrite replaced by Zn2+ has the best match point. The minimum microwave reflection loss is ?36.26 dB under the match thickness of 5.63 mm, and the bandwidth less than ?10 dB can reach 4.7 GHz.
Key words: nickel ferrite; sol-gel method; ion replace; magnetic property; optimization design
