Fabrication and microwave absorbent properties of Cobate zinc substituted W-type BaCoZnFe16O27

Due to higher magnetocrystalline anisotropy field and lower matching thickness, magnetoplumbite (W-) type barium ferrite with a sheet structure have become one of promising wave absorbing materials in higher frequency. Expanding its wave absorbing scope to lower frequency was one of important target for modern bandwidth absorbing material. In present research, W-type ferrite with cobalt and zinc substituted BaCoZnFe16O27 was prepared by a sol-gel method. The structure, surface morphology and wave absorbing properties of ferrites were characterized by XRD, SEM and vector network analyzer respectively. The results indicated that the optimum fabrication process for single phase W-type ferrite was two step calcination for 2 Ii at 450 degrees C and 1200 degrees C. With substitution of Co-Zn, the magnetic anisotropy held and natural resonant frequency of BaCoZnFe16O27 were varied. And just the variation expanded the absorbing properties of W-type barium ferrite to low frequency. Single phase BaCoZnFe16O27 exhibited good wave absorbing properties at 5.5 GHz with the minimum absorption values 18 dB. And the absorption bandwidth was 1 GHz above 5 dB. (C) 2014 Elsevier B.V. All rights reserved