Magnetocrystalline anisotropy in ferrites of the form Zn2X and Co2X

Author

Silber, L.M. ; Tsantes, E.

Author_Institution

Polytechnic Institute of Brooklyn, Brooklyn, NY, USA

Volume

Issue

fYear

1969

fDate

9/1/1969 12:00:00 AM

Firstpage

600

Lastpage

604

Abstract

Measurements of the magnetocrystalline anisotropy have been made in Ba2Zn2Fe28O46and Ba2Co2Fe28O46, two materials of the $X$ phase of hexagonal ferrites. The measurements were made by ferromagnetic resonance techniques at room temperature. The anisotropy of Zn2X was also measured by a static technique. These materials have rhombehedral symmetry, and thus are similar to the $Y$ phase. The lowest terms in the anisotropy energy consistent with this symmetry are $E_{A} = K_{1} \\sin^{2}\\theta + K_{2} \\sin^{4}\\theta + K_{2}\´ \\sin^{3}\\theta\\cos\\theta\\cos 3\\phi$ . Zn2X shows uniaxial anisotropy, with $K_{1} = +2.57 \\times 10^{6}$ erg/cm³, K2and $K_{2}\´$ zero. The static measurement yielded $K_{1} = 2.50 \\times 10^{6}$ erg/cm³. In Co2X $K_{1} = -2.6 \\times 10^{5}$ erg/cm³, $K_{2} = +3.8 \\times 10^{5}$ erg/cm³, $K_{2}\´ = 1.2 \\times 10^{5}$ erg/cm³so the unique axis becomes a hard direction. Comparison of the measured change in anisotropy on substitution of cobalt for zinc with the theory of Slonczewski shows that to second order the theory predicts just the three terms shown, and gives numerical values larger by a factor of two than the measured values. Linewidths are also reported.

Keywords

Cobalt alloys; Ferrites; Magnetic anisotropy; Magnetic measurements; Anisotropic magnetoresistance; Ferrites; Iron; Magnetic anisotropy; Magnetic materials; Magnetic resonance; Perpendicular magnetic anisotropy; Phase measurement; Temperature; Zinc;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.1969.1066556

Filename

1066556

Link To Document

https://search.isc.ac/dl/search/defaultta.aspx?DTC=49&DC=1040639