TiO2 Enhanced Magnetic-Dielectric Properties of Co2Z Ferrite Materials for High Frequency Applications

Hexagonal ferrite Ba3Co2Fe24-xTixO41 (x = 0.0-0.6) was synthesized via a solid-state reaction method and their magnetic and dielectric properties were investigated. The crystallographic phase analysis showed that all the samples were mainly single Z-type hexagonal ferrite Ba3Co2Fe24O41 (Co(2)Z) formations, with slightly Y-type hexagonal ferrite as the second phase. The micromorphology images showed that the grains of all the samples had a typical hexagonal structure and that the grain size decreased with the addition of TiO2. The hysteresis loops showed that all the samples possessed a typical soft magnetic performance. With the increase of x, the grain size increased, the saturation magnetization (M-S) gradually rose, and the coercivity (H-C) first increased and then decreased slightly. Appropriate amounts of Ti4+ ion could enhance the magnetic permeability and the dielectric permittivity of Co(2)Z ferrite. When x = 0.2, the material possessed a high real part of magnetic permeability (mu ' = 9.32) and real part of dielectric permittivity (epsilon ' = 17.61), and kept a low magnetic loss (tan delta(mu)approximate to 0.06) and dielectric loss (tan delta(epsilon )approximate to 0.002) in the frequency range of 10 MHz-1 GHz. These results indicated that Ti4+-substituted Co(2)Z ferrites were suitable for antenna and filter applications in the high frequency.