Influence of MgTiO3 on the magnetic and dielectric properties of Ba3Co2Fe24O41 hexaferrite

MgTiO3-doped Ba3Co2Fe24O41 hexaferrites (Co(2)Z) have been prepared by the solid-state reaction method, and the magnetic and dielectric properties have been investigated. Permeability measurements indicate that MgTiO3 doping significantly improves the frequency characteristics of permeability, i.e., with the increase of MgTiO3 doping content from 0 to 5 wt %, the cutoff frequency increases greatly from 0.33 GHz to > 1.8 GHz. Although mu' decreases from 16.1 to 5.4 in a sample doped with 5 wt % MgTiO3, magnetic loss mu '' is effectively suppressed in frequency above 300 MHz. The permittivity of 5 wt % MgTiO3 doped specimen keeps stable in the value of about 17, while the dielectric loss largely decreases in the frequency rang from 300 MHz to 1.8 GHz. The low magnetic and dielectric loss and the improvement of frequency characteristics are crucial for high-frequency antenna applications of Z-type hexaferrites. (C) 2010 American Institute of Physics. [doi:10.1063/1.3338692]