本研究的目的為研究出中心頻率在5GHz、厚度小於4.5mm、-10dB頻寬達到3GHz、-20dB頻寬達到1GHz的複合吸波材料，主要材料為磁性材料/介電材料/高分子聚合物的複合材料，透過調整(Ni0.5-0.5xZn0.5-0.5xCox)Fe2O4的莫耳比例x、製備時的煆燒溫度，選擇出具最佳磁損耗的粉體，並將粉體與奈米碳纖維(CNF)以及奈米碳管(CNT)製作成複合試片，並調整兩種不同碳材料的摻雜比例，以此找出最佳的摻雜量。結果顯示(Ni0.5-0.5xZn0.5-0.5xCox)Fe2O4/Epoxy的介電損耗相當低，在2~18GHz間介電損耗正切均小於0.1，單獨摻雜鐵氧粉體時主要依靠磁損耗提供吸波能力並且在2~7GHz間具較高的磁損耗正切值，在煆燒溫度1200℃下製備出的(Ni0.45Zn0.45Co0.1)Fe2O4/Epoxy試片在5GHz處有最大的磁損耗正切0.51，推算出的反射損耗為-16.3dB，試片厚度為6.2mm。其次為了增加介電損耗摻入CNF，結果顯示摻入CNF後介電損耗正切值有明顯的提升，未摻雜CNF時介電損耗正切僅有0.05的平均值在摻入CNF後皆可超過0.15，但摻入CNF亦會使得磁損耗正切下降。當CNF摻雜量為0.5wt%的(Ni0.45Zn0.45Co0.1)Fe2O4/Epoxy/CNF複合試片，在中心頻率5GHz時最大反射損耗為-31dB，並達到-10dB頻寬2.6GHz、以及-20dB頻寬0.8GHz、厚度為4.8mm，單獨摻雜0.5wt%的CNT試片在中心頻率5GHz處所能達到的最大反射損耗為-11.7dB，厚度為6mm，對比單獨摻雜0.5wt%的CNF試片效果較差，推測為CNT試片分散性不佳，因此若能做好分散性的處理將有機會改善。在同時摻雜CNT以及CNF的情況下，0.5wt%的CNF以及0.25wt%的CNT複合試片，在中心頻率5GHz處時厚度為5.2mm，最大反射損耗為-25.9dB，達到-20dB的頻寬為0.8GHz達到-10dB的頻寬為4GHz，在-10dB頻寬有所提升但厚度亦增加。綜合在5GHz上的應用，單獨摻雜0.5wt%的CNF所達到的在中心頻率5GHz時最大反射損耗為-31dB，-10dB頻寬2.6GHz以及-20dB頻寬0.8GHz厚度為4.8mm較為接近預設目標。本研究對於(Ni0.45Zn0.45Co0.1)Fe2O4/Epoxy/CNF/以及(Ni0.45Zn0.45Co0.1)Fe2O4/Epoxy/CNF/CNT的元素比例、煆燒溫度、CNF及CNT摻雜比例影響已有提出，將此材料當作基準可以作為設計先進微波吸收材料的參考。

This work first studied the effects of sintering temperature and mole ratio x(=0.1, 0.2, 0.3) on complex permeability and magnetic loss tangent of composite (Ni0.5-0.5xZn0.5-0.5xCox)Fe2O4/Epoxy as microwave absorbing material. The result showed that the maximum magnetic loss tangent of 0.51 at 5 GHz was found for sintering temperature of 1200℃ and x = 0.1. Theoretical computation suggested that -16.3 dB of reflection loss could be obtained for the composite material of thickness of 6.2 mm, backed on a metal plate. Furthermore, carbon nanofiber (CNF) and carbon nanotube (CNT) were added into the composite material to improve dielectric loss tangent. The result showed that the sole addition of 0.5wt%-CNF had the best expectation with the lowest reflection loss of -31dB at 5 GHz and smaller thickness of 4.8 mm.

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