Fe–Pd thin films as a model system for self-organized exchange coupled nanomagnets

Abstract

In equilibrium the Fe–Pd system on the iron rich side of the phase diagram demixes into Fe and L10-ordered FePd. Here, we examine the suitability of the demixing process for self-organized formation of exchange coupled thin film magnets. In this way the benefit of the high magnetization of Fe is combined with the high magnetocrystalline anisotropy of FePd. By using combinatorial methods the influence of composition and thickness on structure, microstructure, and magnetic properties is analyzed. Experiments show the different thermodynamic and kinetic conditions required for demixing and ordering. In particular, for nanostructures the interface energy during demixing must be considered.

Control of c-axis orientation of L1-FePd in dual-phase-equilibrium FePd/Fe thin films

“…[15][16][17][18] A well-known problem raised recently is that the switching magnetic field is still too high for write applications due to the high anisotropy field caused by the large K. In order to ameliorate this condition, a composite of soft and hard magnetic materials is effective in reducing the switching field. 19,20 As a model case, we have recently reported the exchange-coupling magnetic property of the ␣-Fe/ L1 0 -FePd dual-phase region in the Fe-Pd alloy system, 21 and Schied et al 22 also reported recently the exchange-coupling behavior of this same system. The Fe-Pd alloy system is attractive in that the soft magnetic ␣-Fe and hard magnetic L1 0 -FePd coexist in thermal equilibrium.…”

Determination of grain shape of laser-irradiated FePdCu thin alloy films

“…The FePd alloy is promising candidate for Bit Patterned Media technology due to its strong perpendicular magnetic anisotropy. [7] However, this feature appears only in alloys with L1 0 structure, epitaxial or polycrystalline with strong (001) texture. [8] The tetragonal L1 0 structure with the alternating planes of Fe and Pd atoms is the anisotropic crystal with strong magnetocrystalline anisotropy.…”

Structural ordering of laser-processed FePdCu thin alloy films

“…The development of new materials for the magnetic storage industry requires investigation of the new methods of their fabrication. Magnetic thin alloy films with L1 0 crystal structure such as FePd, FePt and CoPt, which exhibit a large uniaxial magnetic anisotropy of a few MJ/m 3 , [1][2][3][4] are considered as potential materials for the bit pattern high-density recording media with information density over 1 Tbit/in 2 . Application of these materials in data storage devices with perpendicular recording requires the fabrication of (001)textured film.…”