Impact of Gd dopants on current polarization and the resulting effect on spin-transfer velocity in Permalloy wires

Published

August 1, 2011

Author(s)

Rebecca L. Thomas, Meng Zhu, Cindi L. Dennis, Veena Misra, Robert McMichael

Abstract

A spin-wave Doppler technique is used to measure the spin-transfer velocity and the current polarization in current-carrying (Ni80Fe20)1-xGdx alloy wires. Reduced magnetization values with Gd doping suggest possible increases in the spin-transfer velocity. Contrary to these expectations, we measured a decrease in the spin-transfer velocity upon introducing Gd dopants. For a current density of 1011 A/m2, the measured velocities range from 6.0 ± 0.6 m/s for pure Permalloy to 2.6 ± 0.3 m/s for (Ni80Fe20)94.5Gd5.5. Interpretation of these values yields a current polarization ranging from .71 ± .02 to .30 ± .01 for the same compositions. These results reveal that Gd dopants in Permalloy have a more significant impact on the current polarization than on the material's magnetization for these alloy compositions.

Citation

Journal of Applied Physics

Volume

110

Issue

3

Pub Type

Journals

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Keywords

nanomagnetics, spin, future electronics, spin waves, magnetism

Citation

Thomas, R. , Zhu, M. , Dennis, C. , Misra, V. and McMichael, R. (2011), Impact of Gd dopants on current polarization and the resulting effect on spin-transfer velocity in Permalloy wires, Journal of Applied Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=908389 (Accessed October 20, 2025)