Magnetic studies of Sn2+–Sn4+-substituted barium hexaferrites synthesized by mechanical alloying

• Published in: Materials letters Vol. 58; no. 22-23; pp. 2906 - 2910
• Main Authors: Gonzalez-Angeles, A, Mendoza-Suarez, G, Gruskova, A, Dosoudil, R, Ortega-Zempoalteca, R
• Format: Journal Article
• Language: English
• Published: 01.09.2004
• ISSN: 0167-577X
• DOI: 10.1016/j.matlet.2004.05.017

The effect of Sn2+-Sn4+ mixture on magnetic properties of BaM has been studied by Mossbauer spectroscopy and vibrating sample magnetometry. The results show that the magnetization reached a maximum for x=0.2 and then diminished. Mossbauer spectra showed that Sn2+-Sn4+ ions preferentially occupy 2b and 4f2 sites, followed by 4f1 and 2a sites; whilst the 12k was the least affected by the substitution. The preference for the 4f2 and 4f1 sites is responsible for the increase in the magnetization at low substitutions, due to their spin down configuration. At x # > 0.3 values, a steep drop of both Ms and Mr was recorded, which might be due to the appearance of small amounts of tin oxide (SnO2) as a secondary phase. A large variation of the intrinsic coercivity, Hci, (4.8 to 0.909 kOe) was obtained as a function of the substitution. The rapid decrease of Hci has its origin in the preference of Sn2+-Sn4 ions for the 2b and 4f2 sites.