Origin of Cross-Over Phenomenon of Hysteresis Loops and High Absorption Loss Properties for Spinel Ferrite Nanoparticles

Spinel ferrite nanoparticles have been synthesized by the surfactant-assisted hydrothermal route using cetyltrimethylammonium bromide (CTAB) and ethylenediaminetetraacetic acid (EDTA) in the NaOH solution. Temperature evolution of magnetic hysteresis loops has been investigated in detail. The magnetic characterization of spinel nanoparticles has been measured by a quantum design vibrating sample magnetometer model 6000. The origin of a cross-over feature of ferrite nanoparticles has been observed at room temperature. Microwave properties of ferrites were investigated with the use of an Anritsu MS2028C VNA Master. The present studies also demonstrate that a microwave absorber can be fabricated within a ferrite polymer nanocomposite for technological applications up to 16 GHz, with the reflection loss of more than -60 dB and -50 dB by using CTAB and EDTA, respectively.