Investigation of Ba2Me2Fe12O22 (M = Co, Zn) Hexaferrite Based on External Magnetic Field M¨ossbauer Spectroscopy

Polycrystalline Ba2Me2Fe12O22 (Me = Co, Zn) samples were prepared by using a solid-statereaction method. The crystal structures of samples were determined to be rhombohedral withspace group (R-3m). Based on the magnetic hysteresis curves up to 10 kOe at 4.2 K, we foundthe saturation magnetization (Ms) of Ba2Me2Fe12O22 (Me = Co, Zn) samples to be Ms = 33.2,and 68.6 emu/g, respectively. From the zero-field-cooled (ZFC) magnetization curves under 100 Oebetween at temperatures 4.2 K and 740 K, the Curie temperature (TC) was found to be decreasewith increasing Zn contents. Zero-field M¨ossbauer spectra of the samples were taken at varioustemperatures ranging from 4.2 to 750 K. The isomer shift values of samples showed that the chargestates were Fe3+ high spin. From the M¨ossbauer spectra taken at 4.2 K with external field rangingfrom 0 to 50 kOe, the canting angles between the external field and the hyperfine field of samplescontaining Co and Zn were ' = 34 and 17 , respectively.