Study of Dielectric and Magnetodielectric Properties of Y-Type Ba2Mg1.5Ni0.5Fe12O22 Hexaferrite

We have investigated dielectric and magnetodielectric (MD) properties of polycrystalline Y-type hexaferrite Ba2Mg1.5Ni0.5Fe12O22 (BMNF). Rietveld refinement of the X-ray diffraction pattern and hexagonal plate-like Field Emission Scanning Electron Microscope (FESEM) micrograph confirms the phase purity with the rhombohedral crystal structure (R-3m space group). Both temperatures dependent dielectric permittivity (epsilon') and dielectric loss (tan delta) show an anomaly around 150 degrees C and 290 degrees C. The comparable value of activation energy extracted from impedance spectroscopy above 290 degrees C between sigma(g) and sigma(gb) indicates that relaxation and conduction mechanism may be attributing to the same entities. Room temperature magnetodielectric (MD) measurement at 1MHz indicates the step like increase at similar to 8 kOe in dielectric constant (epsilon) with applied field but a reverse trend is observed for magneto-loss (ML) with step like feature preserving it nature.