Efficient spin transport through native oxides of nickel and permalloy with platinum and gold overlayers

B. L. Zink, M. Manno, L. O'Brien, J. Lotze, M. Weiler, D. Bassett, S. J. Mason, S. T B Goennenwein, M. Johnson, C. Leighton

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

We present measurements of spin pumping detected by the inverse spin Hall effect voltage and ferromagnetic resonance spectroscopy in a series of metallic ferromagnet/normal metal thin film stacks. We compare heterostructures grown in situ to those where either a magnetic or nonmagnetic oxide is introduced between the two metals. The heterostructures, either nickel with a platinum overlayer (Ni/Pt) or the nickel-iron alloy permalloy (Py) with a gold overlayer (Py/Au), were also characterized in detail using grazing-incidence x-ray reflectivity, Auger electron spectroscopy, and both SQUID and alternating-gradient magnetometry. We verify the presence of oxide layers, characterize layer thickness, composition, and roughness, and probe saturation magnetization, coercivity, and anisotropy. The results show that while the presence of a nonmagnetic oxide at the interface suppresses spin transport from the ferromagnet to the nonmagnetic metal, a thin magnetic oxide (here the native oxide formed on both Py and Ni) somewhat enhances the product of the spin-mixing conductance and the spin Hall angle. We also observe clear evidence of an out-of-plane component of magnetic anisotropy in Ni/Pt samples that is enhanced in the presence of the native oxide, resulting in perpendicular exchange bias. Finally, the dc inverse spin Hall voltages generated at ferromagnetic resonance in our Py/Au samples are large, and suggest values for the spin Hall angle in gold of 0.04<αSH<0.22, in line with the highest values reported for Au. This is interpreted as resulting from Fe impurities. We present indirect evidence that the Au films described here indeed have significant impurity levels.

Original languageEnglish (US)
Article number184401
JournalPhysical Review B
Volume93
Issue number18
DOIs
StatePublished - May 2 2016

Fingerprint

Permalloys (trademark)
Platinum
Gold
Oxides
platinum
Nickel
nickel
gold
oxides
Ferromagnetic resonance
Metals
ferromagnetic resonance
Heterojunctions
Spin Hall effect
Impurities
metals
Iron alloys
Magnetic anisotropy
SQUIDs
Nickel alloys

How much support was provided by MRSEC?

  • Partial

Reporting period for MRSEC

  • Period 3

Cite this

Efficient spin transport through native oxides of nickel and permalloy with platinum and gold overlayers. / Zink, B. L.; Manno, M.; O'Brien, L.; Lotze, J.; Weiler, M.; Bassett, D.; Mason, S. J.; Goennenwein, S. T B; Johnson, M.; Leighton, C.

In: Physical Review B, Vol. 93, No. 18, 184401, 02.05.2016.

Research output: Contribution to journalArticle

Zink, BL, Manno, M, O'Brien, L, Lotze, J, Weiler, M, Bassett, D, Mason, SJ, Goennenwein, STB, Johnson, M & Leighton, C 2016, 'Efficient spin transport through native oxides of nickel and permalloy with platinum and gold overlayers', Physical Review B, vol. 93, no. 18, 184401. https://doi.org/10.1103/PhysRevB.93.184401
Zink, B. L. ; Manno, M. ; O'Brien, L. ; Lotze, J. ; Weiler, M. ; Bassett, D. ; Mason, S. J. ; Goennenwein, S. T B ; Johnson, M. ; Leighton, C. / Efficient spin transport through native oxides of nickel and permalloy with platinum and gold overlayers. In: Physical Review B. 2016 ; Vol. 93, No. 18.
@article{f42083fe0abb47a09a15ac7a5cd34b6d,
title = "Efficient spin transport through native oxides of nickel and permalloy with platinum and gold overlayers",
abstract = "We present measurements of spin pumping detected by the inverse spin Hall effect voltage and ferromagnetic resonance spectroscopy in a series of metallic ferromagnet/normal metal thin film stacks. We compare heterostructures grown in situ to those where either a magnetic or nonmagnetic oxide is introduced between the two metals. The heterostructures, either nickel with a platinum overlayer (Ni/Pt) or the nickel-iron alloy permalloy (Py) with a gold overlayer (Py/Au), were also characterized in detail using grazing-incidence x-ray reflectivity, Auger electron spectroscopy, and both SQUID and alternating-gradient magnetometry. We verify the presence of oxide layers, characterize layer thickness, composition, and roughness, and probe saturation magnetization, coercivity, and anisotropy. The results show that while the presence of a nonmagnetic oxide at the interface suppresses spin transport from the ferromagnet to the nonmagnetic metal, a thin magnetic oxide (here the native oxide formed on both Py and Ni) somewhat enhances the product of the spin-mixing conductance and the spin Hall angle. We also observe clear evidence of an out-of-plane component of magnetic anisotropy in Ni/Pt samples that is enhanced in the presence of the native oxide, resulting in perpendicular exchange bias. Finally, the dc inverse spin Hall voltages generated at ferromagnetic resonance in our Py/Au samples are large, and suggest values for the spin Hall angle in gold of 0.04<αSH<0.22, in line with the highest values reported for Au. This is interpreted as resulting from Fe impurities. We present indirect evidence that the Au films described here indeed have significant impurity levels.",
author = "Zink, {B. L.} and M. Manno and L. O'Brien and J. Lotze and M. Weiler and D. Bassett and Mason, {S. J.} and Goennenwein, {S. T B} and M. Johnson and C. Leighton",
year = "2016",
month = "5",
day = "2",
doi = "10.1103/PhysRevB.93.184401",
language = "English (US)",
volume = "93",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "18",

}

TY - JOUR

T1 - Efficient spin transport through native oxides of nickel and permalloy with platinum and gold overlayers

AU - Zink, B. L.

AU - Manno, M.

AU - O'Brien, L.

AU - Lotze, J.

AU - Weiler, M.

AU - Bassett, D.

AU - Mason, S. J.

AU - Goennenwein, S. T B

AU - Johnson, M.

AU - Leighton, C.

PY - 2016/5/2

Y1 - 2016/5/2

N2 - We present measurements of spin pumping detected by the inverse spin Hall effect voltage and ferromagnetic resonance spectroscopy in a series of metallic ferromagnet/normal metal thin film stacks. We compare heterostructures grown in situ to those where either a magnetic or nonmagnetic oxide is introduced between the two metals. The heterostructures, either nickel with a platinum overlayer (Ni/Pt) or the nickel-iron alloy permalloy (Py) with a gold overlayer (Py/Au), were also characterized in detail using grazing-incidence x-ray reflectivity, Auger electron spectroscopy, and both SQUID and alternating-gradient magnetometry. We verify the presence of oxide layers, characterize layer thickness, composition, and roughness, and probe saturation magnetization, coercivity, and anisotropy. The results show that while the presence of a nonmagnetic oxide at the interface suppresses spin transport from the ferromagnet to the nonmagnetic metal, a thin magnetic oxide (here the native oxide formed on both Py and Ni) somewhat enhances the product of the spin-mixing conductance and the spin Hall angle. We also observe clear evidence of an out-of-plane component of magnetic anisotropy in Ni/Pt samples that is enhanced in the presence of the native oxide, resulting in perpendicular exchange bias. Finally, the dc inverse spin Hall voltages generated at ferromagnetic resonance in our Py/Au samples are large, and suggest values for the spin Hall angle in gold of 0.04<αSH<0.22, in line with the highest values reported for Au. This is interpreted as resulting from Fe impurities. We present indirect evidence that the Au films described here indeed have significant impurity levels.

AB - We present measurements of spin pumping detected by the inverse spin Hall effect voltage and ferromagnetic resonance spectroscopy in a series of metallic ferromagnet/normal metal thin film stacks. We compare heterostructures grown in situ to those where either a magnetic or nonmagnetic oxide is introduced between the two metals. The heterostructures, either nickel with a platinum overlayer (Ni/Pt) or the nickel-iron alloy permalloy (Py) with a gold overlayer (Py/Au), were also characterized in detail using grazing-incidence x-ray reflectivity, Auger electron spectroscopy, and both SQUID and alternating-gradient magnetometry. We verify the presence of oxide layers, characterize layer thickness, composition, and roughness, and probe saturation magnetization, coercivity, and anisotropy. The results show that while the presence of a nonmagnetic oxide at the interface suppresses spin transport from the ferromagnet to the nonmagnetic metal, a thin magnetic oxide (here the native oxide formed on both Py and Ni) somewhat enhances the product of the spin-mixing conductance and the spin Hall angle. We also observe clear evidence of an out-of-plane component of magnetic anisotropy in Ni/Pt samples that is enhanced in the presence of the native oxide, resulting in perpendicular exchange bias. Finally, the dc inverse spin Hall voltages generated at ferromagnetic resonance in our Py/Au samples are large, and suggest values for the spin Hall angle in gold of 0.04<αSH<0.22, in line with the highest values reported for Au. This is interpreted as resulting from Fe impurities. We present indirect evidence that the Au films described here indeed have significant impurity levels.

UR - http://www.scopus.com/inward/record.url?scp=84966311932&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84966311932&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.93.184401

DO - 10.1103/PhysRevB.93.184401

M3 - Article

AN - SCOPUS:84966311932

VL - 93

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 18

M1 - 184401

ER -