Theory of magnetic enhancement in strontium hexaferrite through Zn-Sn pair substitution

Journal Article · Sun Dec 01 00:00:00 EST 2013 · Journal of Magnetism and Magnetic Materials

DOI:https://doi.org/10.1016/j.jmmm.2013.08.006· OSTI ID:1211064

Liyanage, LSI; Kim, S; Hong, YK; Park, JH; Erwin, SC; Kim, SG

We study the site occupancy and magnetic properties of Zn-Sn substituted M-type Sr-hexaferrite SrFe12-x(Zn0.5Sn0.5)(x)O-19 with x=1 using first-principles total-energy calculations. We find that in the lowest-energy configuration Zn2+ and Sn4+ ions preferentially occupy the 4f(1) and 4f(2) sites, respectively, in contrast to the model previously suggested by Ghasemi et al. [J. Appl. Phys, 107, 09A734 (2010)], where Zn2+ and Sn4+ ions occupy the 2b and 4f(2) sites. Density-functional theory calculations show that our model has a lower total energy by more than 0.2 eV per unit cell compared to Ghasemi's model. More importantly, the latter does not show an increase in saturation magnetization (M-s) compared to the pure M-type Sr-hexaferrite, in disagreement with the experiment. On the other hand, our model correctly predicts a rapid increase in M-s as well as a decrease in magnetic anisotropy compared to the pure M-type Sr-hexaferrite, consistent with experimental measurements. (c) 2013 Elsevier B.V. All rights reserved.

• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• DOE Contract Number: DE-AR0000189
• OSTI ID: 1211064
• Journal Information: Journal of Magnetism and Magnetic Materials, Vol. 348; ISSN 0304-8853
• Country of Publication: United States
• Language: English