Crystallographically textured self-biased W-type hexaferrites for X-band microwave applications

Abstract

We report the magnetic and structural properties of a series of W-type barium hexaferrites of composition BaZn2−xCoxFe16O27, where x = 0.15, 0.20, and 0.25. The anisotropy field of these barium ferrites (BaW) decreased with the substitution of divalent Co ions, while they maintained crystallographic c-axis texture. The measured anisotropy field was ∼10 kOe, and a hysteresis loop squareness Mr/Ms = 79% was obtained due to well-controlled grain size within the range of single domain scale. These two properties make the BaW suitable for applications in microwave devices at lower frequencies, such as self-biased circulators operated at X-band frequencies.