Influence of microstructure on magnetic and dielectric performance of Bi2O3-doped Mg Cd ferrites for high frequency antennas

The effects of microstructure on the magnetic and dielectric properties of Mg(0.6)Cd(0.4)CO(0.05)Fe(1.95)o(4) spinet ferrites with the addition of 2.5 wt% Bi2O3 are investigated mainly for high frequency applications. The measurement results reveal that composites processed via low temperature co-fired ceramic (LTCC) technology at different sintering temperatures (900 degrees C, 920 degrees C, 930 degrees C, and 940 degrees C) possess excellent equivalent permeability (mu') and permittivity (epsilon') (at 940 degrees C, mu' approximate to epsilon' approximate to 25), over a long frequency range from 1 to 100 MHz. The results also indicate that densification sintering results in ultra low dielectric loss tans, and magnetic loss tan delta(mu) (tan delta(epsilon) approximate to 0.003, tan delta(mu) approximate to 0.035). In addition, the samples present enhanced magnetic properties, such as high saturation magnetization (approximately 37.94 emu/g) and appropriate coercivity (approximately 60.5 Oe) at 940 degrees C. This research presents the prospect of wide application of Mg-Cd ferrites in high frequency applications.