Low-temperature Sintered Y-type Hexagonal Ferrites with High Permeability

Abstract

Low-temperature sintering Y-type hexagonal femtes were made by the ceramics method. The temperature obtaining a single phase shifted lower with the CuO content. In Ba₂Co_1.0Cu_1.0Fe₁₂O₂₂, a single phase was obtained at 950°C calcination. At the same time, the shrinkage curve shifts to the low temperature, and the firing temperature that is able to get over 95% of the theoretical density has lowered from 1200°C to 1000°C by the CuO substitution. Further more, Bi₂O₃ addition shifted the shrinkage curve to the low temperature. Exact sintered body with 900°C sintering was obtained by 5 wt% addition. The permeability and resonance frequency were 2.3 and 5.7 GHz respectively. The permeability was improved by divalent metal substitution, Ba₂Me_1.0Cu_1.0Fe₁₂O₂₂ (Me: Ni, Mg, Zn), and the highest permeability was achieved by Zn substitution. The permeability and resonance frequency were 9.7 and 1.0 GHz respectively. It is found that Ba₂Zn_xCu_2-xFe₁₂O₂₂ with Bi₂O₃ addition show high performance as magnetic material for chip inductors.