Highly c-axis oriented W-type hexaferrites SrNi2ScxFe16-xO27 (x = 0.70, 0.75, 0.80 and 0.85) for the design of self-biased circulator at Ku band

Abstract

Highly oriented W-type hexaferrites SrNi2ScxFe16-xO27 (SrW, x = 0.70, 0.75, 0.80 and 0.85) are fabricated via ceramic process and magnetic orientation to meet design requirements of self-biased circulators. The orientation degree reaches 0.81 when Sc3+ substitution content x is 0.75. The XRD refinement results in consideration of orientation illustrate the strong c-axis anisotropy texture of SrW. SEM images show significant uniformity in grain growth with c-axis stays vertical to sample plane. Consequently, the corresponding remanence ratio Mr/Ms reaches as high as 0.92, which is indispensable to reduce low field loss (LFL) as much as possible in the design of self-biased circulators. According to simulation results, the self-biased microstrip circulator based on this SrW material (x = 0.75) realizes ideal functions in circular transmission operating at Ku band.