• Mcalmont, Deandre
• Anyumba, Dan
• Negusse, Ezana
• Johnson, Anthony
• Budhani, Ramesh C.

Abstract

<jats:p>Measurements of magnetization [M(H, T)] and anomalous Hall resistance [Rxy(H, T)] are performed over a broad range of magnetic field (H) and temperatures (T) on sputter deposited 10 nm thick films of (FeCo)1−xGdx. The Gd content (x) in the films was changed by varying the Gd source power from 20 W to 50 W, in steps of 5 W. The saturation magnetization (Ms) of these films at 300 K shows a distinct minimum for the source power of 40 W. Measurements of M(H) for the 40 W sample at several temperatures establish full compensation of the antiferromagnetically coupled magnetic sublattices of Gd and FeCo at Tcomp = 270 K ± 10 K. The approach to compensation is characterized by the emergence of perpendicular magnetic anisotropy (PMA) and a diverging coercive field. The Rxy (H) of this sample, as well as of those prepared at 30 W and 50 W, scales with M(H) at T &amp;gt; Tcomp and T &amp;lt; Tcomp. However, this scaling fails in the vicinity of Tcomp where the Rxy undergoes a sign reversal. Our analysis of these data in the framework of the existing models for Rxy(H, T) in ferrimagnets suggests that the role of spin disorder and its topological contribution to Rxy may be necessary to account for the observed behavior. A precise identification of Tcomp is also important to stabilize technologically useful non-trivial spin textures and PMA in these systems.</jats:p>

Topics

• impedance spectroscopy
• amorphous
• mass spectrometry
• texture
• magnetization
• saturation magnetization