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Low magnetic damping and large negative anisotropic magnetoresistance in half-metallic Co2-xMn1+xSi Heusler alloy films grown by molecular beam epitaxy

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.5030341· OSTI ID:1503633
 [1];  [2];  [3];  [3];  [3];  [2]
  1. Tohoku Univ., Sendai (Japan); Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
  2. Univ. of California, Santa Barbara, CA (United States)
  3. Tohoku Univ., Sendai (Japan)
+ Show Author Affiliations

Co2-xMn1+xSi films with various composition x were epitaxially grown using molecular beam epitaxy (MBE). High crystallinity and atomic ordering in the prepared Co2-xMn1+xSi films were observed, and their magnetic damping and anisotropic magnetoresistance (AMR) effect were systematically investigated. An ultra-low magnetic damping constant of 0.0007 was obtained in the Co2-xMn1+xSi film with a valence electron number (NV) of about 29.0. Additionally, a relatively large negative AMR effect was observed in the Co2-xMn1+xSi films that had a NV of about 29.0. This low damping and the large negative AMR effect indicate that epitaxial Co2-xMn1+xSi films with high atomic ordering grown by MBE possess a high-spin polarization.

Half-metals have potential for enhancing the performance of various kinds of spintronic devices, such as magnetic sensors and magnetic random access memory (MRAM) devices, because the conduction electrons are completely spin-polarized due to the Fermi level (EF) being in the energy gap of one of the spin channels. Among the half-metals, Co-based Heusler alloys are expected to show half-metallic properties at room temperature due to their high Curie temperature. In the past decade, high tunnel magnetoresistance (TMR) and current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) have been experimentally demonstrated using Co-based Heusler alloy electrodes. Furthermore, further improvement of their half-metallic properties is required to obtain improved performance in magnetic tunnel junctions (MTJs) and CPP-GMR devices.

Research Organization:
Univ. of California, Santa Barbara, CA (United States)
Sponsoring Organization:
USDOE; USDOE Office of Science (SC)
Grant/Contract Number:
SC0014388
OSTI ID:
1503633
Alternate ID(s):
OSTI ID: 1457492
Journal Information:
Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 26 Vol. 112; ISSN 0003-6951
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

References (36)

Magnetic and chemical order in Heusler alloys containing cobalt and manganese journal January 1971
Gilbert damping constant in polycrystalline CO2MnSi Heusler alloy films journal March 2007
Molecular beam epitaxy growth of ferromagnetic single crystal (001) Ni2MnGa on (001) GaAs journal September 1999
Giant tunneling magnetoresistance in Co2MnSi∕Al–O∕Co2MnSi magnetic tunnel junctions journal May 2006
Large tunnel magnetoresistance in magnetic tunnel junctions using a Co2MnSi Heusler alloy electrode and a MgO barrier journal September 2008
Low damping constant for Co2FeAl Heusler alloy films and its correlation with density of states journal April 2009
Half-metallicity and Gilbert damping constant in Co2FexMn1−xSi Heusler alloys depending on the film composition journal March 2009
Improved tunnel magnetoresistance of magnetic tunnel junctions with Heusler Co2FeAl0.5Si0.5 electrodes fabricated by molecular beam epitaxy journal April 2009
Origin of low Gilbert damping in half metals journal July 2009
Gilbert magnetic damping constant of epitaxially grown Co-based Heusler alloy thin films journal June 2010
Extensive study of giant magnetoresistance properties in half-metallic Co 2 (Fe,Mn)Si-based devices journal December 2012
Half-metallicity and anisotropic magnetoresistance of epitaxial Co 2 FeSi Heusler films journal April 2013
The microstructure, electronic, and magnetic characterization of highly ordered Co 2 MnSi thin films deposited on MgO substrate journal June 2013
Enhancement of giant magnetoresistance by L2 1 ordering in Co 2 Fe(Ge 0.5 Ga 0.5 ) Heusler alloy current-perpendicular-to-plane pseudo spin valves journal July 2013
Ferromagnetic Schottky junctions using half-metallic Co 2 MnSi/diamond heterostructures journal July 2013
Quantitative analysis of anisotropic magnetoresistance in Co 2 MnZ and Co 2 FeZ epitaxial thin films: A facile way to investigate spin-polarization in half-metallic Heusler compounds journal April 2014
Oxygen migration in epitaxial CoFe/MgO/Co 2 MnSi magnetic tunnel junctions journal September 2017
Influence of film composition in quaternary Heusler alloy Co 2 (Mn,Fe)Si thin films on tunnelling magnetoresistance of Co 2 (Mn,Fe)Si/MgO-based magnetic tunnel junctions journal April 2015
First-principles study of the Gilbert damping constants of Heusler alloys based on the torque correlation model journal April 2015
Magnetic damping constant in Co-based full heusler alloy epitaxial films journal April 2015
Structural and Magnetic Properties of Co 2 MnSi Thin Film with a Low Damping Constant journal May 2015
Broad-Band FMR Linewidth of Co 2 MnSi Thin Films with Low Damping Factor: The Role of Two-Magnon Scattering journal April 2016
Slater-Pauling behavior and origin of the half-metallicity of the full-Heusler alloys journal November 2002
Role of structural defects on the half-metallic character of Co 2 MnGe and Co 2 MnSi Heusler alloys journal March 2004
Atomic disorder effects on half-metallicity of the full-Heusler alloys Co 2 ( Cr 1 − x Fe x ) Al : A first-principles study journal April 2004
Thermodynamics of the Heusler alloy Co 2 − x Mn 1 + x Si : A combined density functional theory and cluster expansion study journal March 2009
Anisotropic magnetoresistance in Co 2 (Fe,Mn)Si Heusler epitaxial films: A fingerprint of half-metallicity journal July 2012
Effect of nonstoichiometry on the half-metallic character of Co 2 MnSi investigated through saturation magnetization and tunneling magnetoresistance ratio journal January 2014
Direct evidence for minority spin gap in the C o 2 MnSi Heusler compound journal March 2016
First-principles calculation of the effects of partial alloy disorder on the static and dynamic magnetic properties of Co 2 MnSi journal March 2017
On the Landau–Lifshitz relaxation in ferromagnetic metals journal December 1970
Large Magnetoresistance Effect in Epitaxial Co$_{2}$Fe$_{0.4}$Mn$_{0.6}$Si/Ag/Co$_{2}$Fe$_{0.4}$Mn$_{0.6}$Si Devices journal November 2011
Search for Half-Metallic Compounds in Co 2 MnZ (Z=IIIb, IVb, Vb Element) journal June 1995
Anisotropic Magnetoresistance Effects in Fe, Co, Ni, Fe 4 N, and Half-Metallic Ferromagnet: A Systematic Analysis journal February 2012
CPP-GMR study of half-metallic full-Heusler compound Co2(Fe,Mn)Si journal January 2014
Anisotropic Magnetoresistance Effect: General Expression of AMR Ratio and Intuitive Explanation for Sign of AMR Ratio journal August 2013

Cited By (4)

Large negative anisotropic magnetoresistance in Co 2 MnGa Heusler alloy epitaxial thin films journal September 2018
Giant anisotropic magnetoresistance and planar Hall effect in Sr 0.06 Bi 2 Se 3 journal November 2018
Polycrystalline Co 2 Mn-based Heusler thin films with high spin polarization and low magnetic damping journal October 2019
Ultralow Magnetic Damping in Co 2 Mn -Based Heusler Compounds: Promising Materials for Spintronics journal June 2019

Figures / Tables (5)

FIG. 1.(p. 3)figure FIG. 1.
FIG. 2.(p. 3)figure FIG. 2.
FIG. 3.(p. 4)figure FIG. 3.
FIG. 4.(p. 4)figure FIG. 4.
FIG. 5.(p. 5)figure FIG. 5.

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