Effects of Ba‐substitution on structural and multiferroic characteristics of Z‐type hexaferrite ceramics

Abstract Ba x Sr 3‐ x Co 2 Fe 24 O 41 ( x = 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0) ceramics were synthesized via a standard solid‐state reaction process to investigate the effects of Ba‐substitution on their structural, ferromagnetic, ferroelectric, and magnetodielectric characteristics. Ba‐substitution effectively stabilized the Z‐type phase, mitigated Sr segregation, and enhanced both grain growth and saturation magnetization ( M s). With increasing x , the Fe‐O‐Fe bond angles at the junction of the magnetic blocks decreased, leading to reduced magnetic frustration and decreased stability of the transverse conical magnetic structure. For x ≤ 2.0, a saturated ferroelectric hysteresis loop was observed at 100 K. Notably, the study revealed a complex relationship between the magnetodielectric effect and the substitution level, with optimal coupling coefficients observed at x = 0.5. The results also suggested that the magnetoelectric effect in Z‐type hexaferrites might arise from a synergistic interplay between inverse Dzyaloshinskii–Moriya interactions and p ‐ d hybridization mechanisms.