Stojak K.,University of South Florida |
Pal S.,University of South Florida |
Srikanth H.,University of South Florida |
Morales C.,Center for Wireless and Microwave Information Systems |
And 3 more authors.
Nanotechnology | Year: 2011
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 (10nm ± 1) into the polymer matrix. Magnetic measurements indicate superparamagnetic response near room temperature for all PNCs. A blocking temperature TB ∼ 298K was observed and does not vary for different loading fractions of CFO NPs for the PNCs. The saturation magnetization (Ms) was found to be 11 emu g-1 for 30wt% CFO, increasing to 32 emu g-1 for the 80wt% CFO loaded PNC. A large value of coercivity (Hc = 19 kOe) is also observed at 10 K and is not affected by varying CFO loading. Microwave measurements show significant absorption in the 80wt% CFO loading PNC and the quality factor shows a strong enhancement with applied magnetic field. © 2011 IOP Publishing Ltd.