Integrated Functional Materials Group, Department of Physics, University of South Florida, Tampa, FL 33620, USA.
Nanotechnology. 2011 Apr 1;22(13):135602. doi: 10.1088/0957-4484/22/13/135602. Epub 2011 Feb 22.
Polymer nanocomposites (PNCs) have been synthesized using Rogers polymer and CoFe₂O₄ nanoparticles (CFO NPs). X-ray diffraction (XRD) confirms the inverse spinel crystal structure of CFO NPs and transmission electron microscopy (TEM) images show the uniform dispersion of nanoparticles (10 nm ± 1) into the polymer matrix. Magnetic measurements indicate superparamagnetic response near room temperature for all PNCs. A blocking temperature T(B)~298 K was observed and does not vary for different loading fractions of CFO NPs for the PNCs. The saturation magnetization (M(s)) was found to be 11 emu g⁻¹ for 30 wt% CFO, increasing to 32 emu g⁻¹ for the 80 wt% CFO loaded PNC. A large value of coercivity (H(c) = 19 kOe) is also observed at 10 K and is not affected by varying CFO loading. Microwave measurements show significant absorption in the 80 wt% CFO loading PNC and the quality factor shows a strong enhancement with applied magnetic field.
聚合物纳米复合材料（PNC）已使用 Rogers 聚合物和 CoFe₂O₄纳米颗粒（CFO NPs）合成。X 射线衍射（XRD）证实了 CFO NPs 的反尖晶石晶体结构，透射电子显微镜（TEM）图像显示纳米颗粒（10nm±1）均匀分散在聚合物基质中。磁性测量表明，所有 PNC 均在室温附近表现出超顺磁响应。观察到一个阻塞温度 T（B）~298 K，并且对于 PNC 中不同的 CFO NPs 负载分数，它不会变化。发现 30wt% CFO 的饱和磁化强度（M（s））为 11 emu g⁻¹，而 80wt% CFO 负载的 PNC 增加到 32 emu g⁻¹。在 10 K 时还观察到矫顽力（H（c）= 19 kOe）的值很大，并且不受 CFO 负载变化的影响。微波测量显示在 80wt% CFO 负载的 PNC 中有明显的吸收，并且品质因数随着外加磁场的增强而显著增强。
