Microwave Absorption and the Magnetic Hyperthermia Applications of Li_0.3Zn_0.3Co_0.1Fe_2.3O₄Nanoparticles in Multiwalled Carbon Nanotube Matrix

Nanoparticles of Li 0.3 Zn 0.3 Co 0.1 Fe 2.3 O 4 (LZC) were prepared by the sol–gel method and dried in a furnace at ∼200 °C. The dried sample was annealed at 500, 600, 700, and 800 °C for 5 h each. Rietveld analysis of X-ray diffraction patterns confirms the cubic Fd 3̅ m phase formation with lattice parameters ranged from 8.376 up to 8.390 Å and allows the crystallite sizes ( d cryst ) to be estimated. To enhance microwave (MW) absorption as well as the effectiveness for hyperthermia treatment, nanoparticles are taken in the matrix of multiwalled carbon nanotubes (MWCNTs) and the morphology of the so-prepared samples (LZC@MWCNT) was studied by scanning electron microscopy and transmission electron microscopy analyses. Both static and dynamic magnetic properties were investigated on the samples of LZC nanoparticles and compared to those of the samples of LZC@MWCNT. The samples annealed at 500, 600, and 800 °C are excellent candidates in cancer treatment as ac magnetic heating analysis shows that the hyperthermia temperature (42 °C) was successfully achieved for an applied ac magnetic field of 420 Oe and 300 kHz frequency. MW absorption study also reveals that the samples of LZC@MWCNT could be used as a potential MW absorbing material for which a maximum reflection loss ( R L ) of ∼−21 dB was achieved at a frequency of 15.27 GHz for only 1 mm layer thickness.