729 research outputs found
Spin-Hall and Anisotropic Magnetoresistance in Ferrimagnetic Co-Gd / Pt layers
We present the Co-Gd composition dependence of the spin-Hall
magnetoresistance (SMR) and anisotropic magnetoresistance (AMR) for
ferrimagnetic Co100-xGdx / Pt bilayers. With Gd concentration x, its magnetic
moment increasingly competes with the Co moment in the net magnetization. We
find a nearly compensated ferrimagnetic state at x = 24. The AMR changes sign
from positive to negative with increasing x, vanishing near the magnetization
compensation. On the other hand, the SMR does not vary significantly even where
the AMR vanishes. These experimental results indicate that very different
scattering mechanisms are responsible for AMR and SMR. We discuss a possible
origin for the alloy composition dependence.Comment: 31 Pages, 9 figure
Perpendicularly Magnetized Ni / Pt (001) Epitaxial Superlattice
A perpendicularly magnetized ferromagnetic layer is an important building
block for recent/future highdensity spintronic memory applications. This paper
reports on the fabrication of perpendicularly magnetized Ni / Pt superlattices
and the characterization of their structures and magnetic properties. The
optimization of film growth conditions allowed us to grow epitaxial Ni / Pt
(001) superlattices on SrTiO (001) single crystal substrates. We
investigated their structural parameters and magnetic properties as a function
of the Ni layer thickness, and obtained a high uniaxial magnetic anisotropy
energy of 1.9 x 10 erg/cm for a [Ni (4.0 nm) / Pt (1.0 nm)]
superlattice. In order to elucidate the detailed mechanism on perpendicular
magnetic anisotropy for the Ni / Pt (001) superlattices, the experimental
results were compared with the first-principles calculations. It has been found
that the strain effect is a prime source of the emergence of perpendicular
magnetic anisotropy.Comment: 33 pages, 12 figure
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