Abstract

We developed a method to engineer the surface topography of Nb underlayers using surface oxidation followed by low energy Ar ion milling to improve the properties of subsequently deposited magnetic Ni<formula><tex>$_{80}$</tex></formula>Fe<formula><tex>$_{20}$</tex></formula> (Permalloy) thin films. The reduced coercivity H<formula><tex>$_{c}$</tex></formula>, increased remanent squareness, and improved magnetic anisotropy in Ni<formula><tex>$_{80}$</tex></formula>Fe<formula><tex>$_{20}$</tex></formula> thin films deposited on oxidized and subsequently ion milled Nb was found to be primarily due to the reduced roughness of the Nb underlayer, especially at high spatial frequency (&#x003E; 25 &#x03BC;m<formula><tex>$^{-1}$</tex></formula>). The typical results that we obtained for Ni<formula><tex>$_{80}$</tex></formula>Fe<formula><tex>$_{20}$</tex></formula> films 2.4 nm thick deposited on Nb 100 nm thick was an easy axis coercivity H<formula><tex>$_{ce}$</tex></formula> = 3.7 Oe (6 Oe without smoothing), a hard-axis H<formula><tex>$_{ch}$</tex></formula> = 1.5 Oe (5.5 Oe without smoothing), an easy axis remanent squareness Sq<formula><tex>$_{e}$</tex></formula> = M<formula><tex>$_{r}$</tex></formula>/M<formula><tex>$_{s}$</tex></formula> = 0.92, a hard-axis remanent squareness Sq<formula><tex>$_{h}$</tex></formula>= 0.25, and a uniaxial anisotropy H<formula><tex>$_{k}$</tex></formula> of = 6.0 Oe, all measured at T = 10 K. This ion-smoothing technique could potentially be used to improve the properties of magnetic layers in superconducting memory and other magnetoelectronic devices which utilize a thick underlayer that serves as an electrical contact.

Original languageEnglish (US)
JournalIEEE Magnetics Letters
DOIs
StateAccepted/In press - Nov 18 2017

Fingerprint

Magnetic properties
Ions
Coercive force
Thin films
Oxidation
Electrodes
Magnetoelectronics
Magnetic anisotropy
Surface topography
Anisotropy
Surface roughness
Data storage equipment
Engineers

Keywords

  • Magnetic films
  • Magnetic measurements
  • Soft Magnetic Materials

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Improvement in the magnetic properties of NiFe thin films on thick Nb electrodes using oxidation and low energy Ar ion milling. / Singh, Rakesh; Rizzo, Nicholas; Bertram, Michelle; Zheng, Kaiwen; Newman, Nathan.

In: IEEE Magnetics Letters, 18.11.2017.

Research output: Contribution to journalArticle

@article{fa22b8eb35a94c1eab63835c2e0c1265,
title = "Improvement in the magnetic properties of NiFe thin films on thick Nb electrodes using oxidation and low energy Ar ion milling",
abstract = "We developed a method to engineer the surface topography of Nb underlayers using surface oxidation followed by low energy Ar ion milling to improve the properties of subsequently deposited magnetic Ni$_{80}$Fe$_{20}$ (Permalloy) thin films. The reduced coercivity H$_{c}$, increased remanent squareness, and improved magnetic anisotropy in Ni$_{80}$Fe$_{20}$ thin films deposited on oxidized and subsequently ion milled Nb was found to be primarily due to the reduced roughness of the Nb underlayer, especially at high spatial frequency (> 25 μm$^{-1}$). The typical results that we obtained for Ni$_{80}$Fe$_{20}$ films 2.4 nm thick deposited on Nb 100 nm thick was an easy axis coercivity H$_{ce}$ = 3.7 Oe (6 Oe without smoothing), a hard-axis H$_{ch}$ = 1.5 Oe (5.5 Oe without smoothing), an easy axis remanent squareness Sq$_{e}$ = M$_{r}$/M$_{s}$ = 0.92, a hard-axis remanent squareness Sq$_{h}$= 0.25, and a uniaxial anisotropy H$_{k}$ of = 6.0 Oe, all measured at T = 10 K. This ion-smoothing technique could potentially be used to improve the properties of magnetic layers in superconducting memory and other magnetoelectronic devices which utilize a thick underlayer that serves as an electrical contact.",
keywords = "Magnetic films, Magnetic measurements, Soft Magnetic Materials",
author = "Rakesh Singh and Nicholas Rizzo and Michelle Bertram and Kaiwen Zheng and Nathan Newman",
year = "2017",
month = "11",
day = "18",
doi = "10.1109/LMAG.2017.2776079",
language = "English (US)",
journal = "IEEE Magnetics Letters",
issn = "1949-307X",
publisher = "Institute of Electrical and Electronics Engineers Inc.",

}

TY - JOUR

T1 - Improvement in the magnetic properties of NiFe thin films on thick Nb electrodes using oxidation and low energy Ar ion milling

AU - Singh, Rakesh

AU - Rizzo, Nicholas

AU - Bertram, Michelle

AU - Zheng, Kaiwen

AU - Newman, Nathan

PY - 2017/11/18

Y1 - 2017/11/18

N2 - We developed a method to engineer the surface topography of Nb underlayers using surface oxidation followed by low energy Ar ion milling to improve the properties of subsequently deposited magnetic Ni$_{80}$Fe$_{20}$ (Permalloy) thin films. The reduced coercivity H$_{c}$, increased remanent squareness, and improved magnetic anisotropy in Ni$_{80}$Fe$_{20}$ thin films deposited on oxidized and subsequently ion milled Nb was found to be primarily due to the reduced roughness of the Nb underlayer, especially at high spatial frequency (> 25 μm$^{-1}$). The typical results that we obtained for Ni$_{80}$Fe$_{20}$ films 2.4 nm thick deposited on Nb 100 nm thick was an easy axis coercivity H$_{ce}$ = 3.7 Oe (6 Oe without smoothing), a hard-axis H$_{ch}$ = 1.5 Oe (5.5 Oe without smoothing), an easy axis remanent squareness Sq$_{e}$ = M$_{r}$/M$_{s}$ = 0.92, a hard-axis remanent squareness Sq$_{h}$= 0.25, and a uniaxial anisotropy H$_{k}$ of = 6.0 Oe, all measured at T = 10 K. This ion-smoothing technique could potentially be used to improve the properties of magnetic layers in superconducting memory and other magnetoelectronic devices which utilize a thick underlayer that serves as an electrical contact.

AB - We developed a method to engineer the surface topography of Nb underlayers using surface oxidation followed by low energy Ar ion milling to improve the properties of subsequently deposited magnetic Ni$_{80}$Fe$_{20}$ (Permalloy) thin films. The reduced coercivity H$_{c}$, increased remanent squareness, and improved magnetic anisotropy in Ni$_{80}$Fe$_{20}$ thin films deposited on oxidized and subsequently ion milled Nb was found to be primarily due to the reduced roughness of the Nb underlayer, especially at high spatial frequency (> 25 μm$^{-1}$). The typical results that we obtained for Ni$_{80}$Fe$_{20}$ films 2.4 nm thick deposited on Nb 100 nm thick was an easy axis coercivity H$_{ce}$ = 3.7 Oe (6 Oe without smoothing), a hard-axis H$_{ch}$ = 1.5 Oe (5.5 Oe without smoothing), an easy axis remanent squareness Sq$_{e}$ = M$_{r}$/M$_{s}$ = 0.92, a hard-axis remanent squareness Sq$_{h}$= 0.25, and a uniaxial anisotropy H$_{k}$ of = 6.0 Oe, all measured at T = 10 K. This ion-smoothing technique could potentially be used to improve the properties of magnetic layers in superconducting memory and other magnetoelectronic devices which utilize a thick underlayer that serves as an electrical contact.

KW - Magnetic films

KW - Magnetic measurements

KW - Soft Magnetic Materials

UR - http://www.scopus.com/inward/record.url?scp=85035101393&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85035101393&partnerID=8YFLogxK

U2 - 10.1109/LMAG.2017.2776079

DO - 10.1109/LMAG.2017.2776079

M3 - Article

AN - SCOPUS:85035101393

JO - IEEE Magnetics Letters

JF - IEEE Magnetics Letters

SN - 1949-307X

ER -