Khalil Huda F, Elsharkawy Sherif G, Al-Harby Nouf F, El-Batouti Mervette
Electronic Materials Department, Advanced Technology and New Material Institute (ATNMI), City of Scientific Research and Technological Applications (SRTA-City), Alexandria 21934, Egypt.
Basic and Applied Sciences, College of Engineering and Technology, AASTMT, Alexandria 21934, Egypt.
Polymers (Basel). 2024 Aug 28;16(17):2432. doi: 10.3390/polym16172432.
In this study, Zn-Al ferrite/polypyrrole (PPy) nanocomposites were synthesized and thoroughly characterized to explore their potential for microwave applications. X-ray diffraction analysis confirmed the presence of ZnO, AlFeO, and FeO phases, with the crystal size decreasing from 31 nm to 19.6 nm as aluminum content increased. High-resolution transmission electron microscopy (HR-TEM) revealed a distinctive core-shell morphology, where the polypyrrole encapsulates the ZnAlFeO particles. Magnetic measurements showed that decreasing aluminum concentration led to a reduction in both saturation magnetization (Ms) from 75 emu/g to 36 emu/g and remanent magnetization (Mr) from 2.26 emu/g to 2.00 emu/g. Dielectric analysis indicated that both the real (ε') and imaginary (ε″) components of dielectric permittivity decreased with increasing frequency, particularly between 10 and 14 GHz. Furthermore, electrical modulus analysis highlighted the significant impact of aluminum doping on relaxation time (τIP), indicating the presence of interface polarization. Impedance spectroscopy results underscored the dominance of interface polarization at lower frequencies and the presence of strong conduction paths at higher frequencies. These combined magnetic and dielectric loss mechanisms suggest that the Zn-Al ferrite/polypyrrole nanocomposite is a promising candidate for advanced microwave absorption applications.
在本研究中，合成了锌铝铁氧体/聚吡咯（PPy）纳米复合材料，并对其进行了全面表征，以探索其在微波应用方面的潜力。X射线衍射分析证实了ZnO、AlFeO和FeO相的存在，随着铝含量的增加，晶体尺寸从31nm减小到19.6nm。高分辨率透射电子显微镜（HR-TEM）揭示了一种独特的核壳形态，其中聚吡咯包裹着ZnAlFeO颗粒。磁性测量表明，铝浓度的降低导致饱和磁化强度（Ms）从75emu/g降至36emu/g，剩余磁化强度（Mr）从2.26emu/g降至2.00emu/g。介电分析表明，介电常数的实部（ε'）和虚部（ε″）均随频率增加而降低，特别是在10至14GHz之间。此外，电模量分析突出了铝掺杂对弛豫时间（τIP）的显著影响，表明存在界面极化。阻抗谱结果强调了低频下界面极化的主导地位以及高频下强导电路径的存在。这些综合的磁损耗和介电损耗机制表明，锌铝铁氧体/聚吡咯纳米复合材料是先进微波吸收应用的有前途的候选材料。
