Microwave absorption properties of SrFe12O19/ZnFe2O4 composite powders

The composite powders with different weight ratios of strontium hexaferrite to zinc ferrite were prepared using sol-gel technique. The crystal structure, morphology and microwave absorption properties of the composite powders were investigated with XRD, FESEM, TEM and vector network analyzer. The results show that the composite powders consist of SrFe12O19 and ZnFe2O4 phases and the individual particles are typically 100-200 nm in diameter. The relative complex permittivity and permeability of the composite powders are investigated. The composite powder with 15 wt% zinc ferrite possesses good microwave absorption properties. The minimum reflection loss of the composite powder reaches -37 dB at the thickness of 2.2 mm. (c) 2007 Elsevier B.V. All rights reserved.