Microwave absorption properties of hollow microsphere/titania/M-type Ba ferrite nanocomposites

Abstract

Low density composite powders of hollow microsphere/titania/M-type Ba ferrite were prepared using a two-step sol-gel technique. Their electromagnetic wave absorption properties were investigated in the 2–18GHz frequency range. Reflection loss less than −20dB was obtained between 7.5–9.4GHz for paraffin composites containing 25wt% titania over an absorber thickness of 2.0–3.0mm. A minimum reflection loss of −30.1dB was observed at 8.5GHz with a thickness of 2.4mm. The strong electromagnetic absorption properties are due to the introduction of a titania intermediate layer.