Magnetic and Microwave Absorption Properties of Barium Hexaferrites synthesized by sol-gel method with addition of PMMA in various ratios

Abstract

The M-type barium hexaferrite (\(\text{B}\text{a}{\text{F}\text{e}}_{12}{\text{O}}_{19}\)) nanoparticles were synthesized by polymethylmethacrylate (PMMA) assisted sol-gel process. PMMA was used as a template at \(\text{P}\text{M}\text{M}\text{A}/\text{B}\text{a}{\text{F}\text{e}}_{12}{\text{O}}_{19}\) weight ratio of 20/80, 40/60, 60/40% in the synthesis. The X-Ray Diffraction (XRD) and scanning electron microscopy (SEM) have been used to determine the structural, compositional and morphological features of particles. DC magnetic properties have been measured by using electron spin resonance (ESR) spectrometer and vibrating sample magnetometry (VSM) at room temperature. The dielectric, magnetic and microwave properties were studied by reflection/transmission technique in the coaxial waveguide at the frequency range of 2–18 GHz. The results show that the nanorod nanoparticles are ~ 200 nm in length and ~ 40–50 nm in width for the sample with \(\text{P}\text{M}\text{M}\text{A}/\text{B}\text{a}{\text{F}\text{e}}_{12}{\text{O}}_{19}\) weight ratio of 20/80. The minimum reflection loss value of rod-shaped nanoparticles achieves ~ -50 dB with bandwidth of 2.25 GHz at -20 dB.