Rietveld refinement pattern of sample CD1. The lower curve represents the difference between the observed and calculated profiles. Plus (+) marks represent the collected data and tick marks show the positions for the allowed reflections. The agreement factors for x-ray diffraction obtained from the Rietveld analysiswere Rp = 5.47%, Rwp = 6.70%, and χ2= 6.606.
Magnetization curves for samples CA3, CD1, and CC3 at a low field range. In the inset is shown the room temperature magnetization curves for the same samples at the whole field range.
Coercive field as function of particle size for all samples. Symbols represent experimental data whereas the solid line was calculated from Eq.(2).
Temperature variation as a function of time for samples CA3, CC3, and CD1 with an applied field of 68 Oe. The inset shows the same as before for sample CD1, but with different magnetic fields.
SAR as a function of saturation magnetization for different values of the applied field. The inset shows SAR as a function of the coercive field for different magnetic fields.
SAR as a function of the dimensionless magnetic anisotropy parameter for different values of the applied field. Open (closed) symbols represent experimental data (experimental data taking into account a core-shell nanoparticle), while the dashed (solid) line represent the linear response theory calculation (Eq. (1)) for a monodisperse (polydisperse) nanoparticle system.
(a) Dynamic hysteresis simulations calculated from Eq. (3) with f = 500 kHz, and and different values of the anisotropy parameter and dimensionless magnetic field . (b) vs. σ for different values of .
Cobalt-ferrite powder samples parameters.
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