Dielectric properties of Sr3Co2Fe24O41 Z-type hexaferrite

Summary form only given. Z-type hexaferrite Sr₃Co₂Fe₂₄O₄₁ (SCFO) has been reported to exhibit the room temperature magnetoelectric effect with a very high magnetoelectric susceptibility compared with other reported single phase materials. The reported studies on the SCFO are focused on its magnetoelectric coupling and high frequency magnetic properties. A systematical understanding on the high frequency electrical properties of SCFO is still lacking. In this work, the dielectric properties of poly-crystalline SCFO have been investigated as a function of frequency (1-2 GHz) and temperature (153 K-503 K). Results show that both dielectric constant ε\´ and dielectric loss ε" of SCFO increase with increasing temperature, indicating a thermally activated dielectric response. In addition, both ε\´ and ε" decrease with increasing frequency until 0.5 GHz. The dielectric relaxation peak appears above 0.5 GHz and 203 K with its peak frequency decreasing with increasing temperature. The above frequency and temperature dependent ε\´ and ε" could be explained by the Koop\´s theory which takes the dielectric structure as two Maxwell-Wagner type layers. This work can help better application of SCFO in the novel devices.