چکیده
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(BaFe12O19)1x/(Ni0.6Zn0.4Fe2O4)x magnetic nanocomposites with various molar
ratios (x = 0.0, 0.1, 0.2, 0.3) have been synthesized by a physical mixing
method at different temperatures (T = 700C to 900C) and their structure,
morphology, and magnetic properties investigated using x-ray diffraction
analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy,
transmission electron microscopy, and vibrating-sample magnetometry.
The results prove that their magnetic properties were strongly influenced
by the sintering temperature as well as the molar ratio of hard to soft phase.
The magnetization and switching field distribution curves for the nanocomposites
sintered above 800C showed a single smooth hysteresis loop, suggesting
the existence of the exchange spring phenomenon. The variation of the
coercivity, saturation magnetization, and ratio of remanence to saturation
magnetization (Mr/Ms) with the hard-to-soft weight ratio can be explained
based on the role of exchange and dipole interactions in the nanocomposites.
High maximum energy product (BH)max was obtained for the (BaFe12O19)0.9/
(Ni0.6Zn0.4Fe2O4)0.1 sample annealed at 800C.
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