Microwave Shielding Characteristics of PMMA/BiFeO3 Composites

BiFe1-xSmxO3 composites with different samarium (Sm) concentration (x = 5-20%) in were fabricated by the solid-state method. Their structure and magnetic property due to the samarium substitution in BFO3 were analyzed by the X-ray diffractometer and vibration sample magnetometer responses, respectively. The complex permeability (mu = mu' - j mu '') and shielding effectiveness (SE) of powder-resin composites consisting of magnetic particles (BiFe1-xSmxO3) embedded into a dielectric matrix (PMMA) were studied at the microwave frequencies. The samarium concentration dependence of permeability and SE was measured using the free-space method. We found that the magnetic properties of the Sm-substitute BFO3 mainly lead to the shielding effect for the PMMA/BiFe1-xSmxO3 composites. In this paper, we demonstrate the gradual change of the shielding effect and permeability of the PMMA/BiFe1-xSmxO3 composites in the microwave range.