Enhanced saturation magnetization and microwave absorption magnetic properties of Mn-Co-Zr substituted BaM ferrite

Mn-Co-Zr substituted BaM ferrite with enhanced saturation magnetization (Ms) was prepared by so-gel method for high-frequency applications. The substituted single-phase BaM ferrite is prepared by heat treating at 1100 degrees C for 4 h. We used SEM, XRD and VSM (vibrating sample magnetometer) to study the sample's morphology, phase and magnetic properties. SEM result shows the ferrite particle size is reduced from 250 nm to 35 nm as substitution x = 1.2. Though BaM ferrite is traditionally a permanent magnetic material, VSM measurements indicate it becomes soft magnetic material after substituting the Mn-Co-Zr ions. The coercivity (Hc) and Ms are 3658 Oe and 58.8 emu/g for x = 0.2, and it becomes 317 Oe and 48.7 emu/g for x = 1.2. Vector network analyzer (VNA) was employed to investigate the high-frequency electromagnetic properties of the ferrite. It was found that the resonance peak decreases as x increases. The reflection loss (RL) is smaller than 10 dB for frequency ranges of 7.2-12.2 GHz and smaller than 20 dB for 9.1-10.6 GHz. The maximum RL is 23 dB at frequency of 9.7 GHz for x = 1.2. Mn-Co-Zr substituted BaM ferrite might be a good candidate for electromagnetic compatibility and for other applications at high frequencies. (C) 2016 Elsevier B.V. All rights reserved.