Crystallographically oriented W-type barium hexaferrite BaZn 2 Fe 16−x Sc x O 27 with high squareness ratio

A series of oriented W-type barium hexaferrites of composition BaZn2Fe16−xScxO27 (where x = 0, 0.1, 0.2, 0.3, 0.4) has been synthesized by conventional ceramic methods and characterized by XRD, SEM, EDS, FTIR, and VSM. In this work, the effect of trivalent Sc substitution for trivalent Fe on the structure and magnetic properties of Zn2W has been studied. The XRD results showed that all the specimens consisted of single phase of W-type ferrites. EDS analysis confirmed that the content of Ba, Zn, Sc, and Fe were closed to the elemental composition of BaZn2Fe16−xScxO27. The SEM revealed the hexagonal platelet-like structure of the BaZn2Fe16−xScxO27 and the average grain sizes of all samples remain in the range of single domain dimension (0.5 µm ~ 1 µm). The SEM also demonstrated that the samples maintained high crystallographic c-axis texture when Sc3+ content was less than 0.4. The SEM results were consistent with magnetic hysteresis loops. As the function of Sc substitution, the squareness ratio (Mr/Ms) ranged from 0.78 to 0.82, which was critical for self-biased application. Moreover, the magnetocrystalline anisotropy field (Ha) decreased. The saturation magnetization (Ms) increased from 53.61 to 54.04 emu/g as x increased from 0 to 0.1, and then it decreased to 46.50 when x > 0.1. The samples showed other excellent magnetic properties, such as appropriate anisotropy field (~ 9 kOe),and high coercive fields (~ 1300 Oe). Therefore, the prepared Zn2W ferrites are suitable candidate for the microwave devices operated at low frequency.