Electromagnetic properties of lithium zinc ferrites doped with aluminum

We present the results of the effect of Al substitution on the magnetic and electrical properties of Li_0.2Zn_0.6Fe_2.2−xAl_xO₄ ferrites (0.0≤x≤0.5) prepared by the standard ceramic technique. The characterization has been performed using XRD, SEM, magnetic and dielectric response in frequency. XRD analysis confirms that the system exhibits polycrystalline single phase cubic spinel structure only for low dopant content. Doping decreases the dielectric loss tangent and the ferrite conductivity in more than two orders of magnitude in the whole analyzed frequency range. Attenuation has a maximum intensity (86 dB) near 90 MHz for x=0.4. The wider bandwidth at 20 dB (94.6 MHz) is for x=0.3.