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Title: Perpendicular magnetic anisotropy of TiN buffered Co 2 FeAl/MgO bilayers

Authors:
ORCiD logo [1];  [1];  [1];  [2];  [1];  [3];  [1]
  1. Center for Spinelectronic Materials and Devices, Bielefeld University, Bielefeld, Germany
  2. Center for Spinelectronic Materials and Devices, Bielefeld University, Bielefeld, Germany, Nanotechnology Centre, VŠB-Technical University of Ostrava, Ostrava, Czech Republic
  3. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1361921
Grant/Contract Number:
AC02-05CH11231
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 121; Journal Issue: 22; Related Information: CHORUS Timestamp: 2018-02-14 11:18:35; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Niesen, Alessia, Ludwig, Jana, Glas, Manuel, Silber, Robin, Schmalhorst, Jan-Michael, Arenholz, Elke, and Reiss, Günter. Perpendicular magnetic anisotropy of TiN buffered Co 2 FeAl/MgO bilayers. United States: N. p., 2017. Web. doi:10.1063/1.4984891.
Niesen, Alessia, Ludwig, Jana, Glas, Manuel, Silber, Robin, Schmalhorst, Jan-Michael, Arenholz, Elke, & Reiss, Günter. Perpendicular magnetic anisotropy of TiN buffered Co 2 FeAl/MgO bilayers. United States. doi:10.1063/1.4984891.
Niesen, Alessia, Ludwig, Jana, Glas, Manuel, Silber, Robin, Schmalhorst, Jan-Michael, Arenholz, Elke, and Reiss, Günter. Wed . "Perpendicular magnetic anisotropy of TiN buffered Co 2 FeAl/MgO bilayers". United States. doi:10.1063/1.4984891.
@article{osti_1361921,
title = {Perpendicular magnetic anisotropy of TiN buffered Co 2 FeAl/MgO bilayers},
author = {Niesen, Alessia and Ludwig, Jana and Glas, Manuel and Silber, Robin and Schmalhorst, Jan-Michael and Arenholz, Elke and Reiss, Günter},
abstractNote = {},
doi = {10.1063/1.4984891},
journal = {Journal of Applied Physics},
number = 22,
volume = 121,
place = {United States},
year = {Wed Jun 14 00:00:00 EDT 2017},
month = {Wed Jun 14 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on June 8, 2018
Publisher's Accepted Manuscript

Citation Metrics:
Cited by: 1work
Citation information provided by
Web of Science

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  • We investigate the role of Pt on the magnetization dynamics of Pt/Co{sub 2}FeAl{sub 0.5}Si{sub 0.5}/MgO with perpendicular magnetic anisotropy using the time resolved magneto-optic Kerr effect. Pt/Co{sub 2}FeAl{sub 0.5}Si{sub 0.5}/MgO shows ultrafast magnetization dynamics comparable to 3d ferromagnets and can be fully demagnetized. The demagnetization time τ{sub d} ∼ 0.27 ps and magnetic heat capacity are independent of the Pt underlayer, whereas the value of the electron-phonon coupling time τ{sub e} ∼ 0.77 ps depends on the presence of the Pt layer. We further measure the effective damping α{sub eff} ∼ 1 that does not scale as the inverse demagnetizationmore » time (1/τ{sub d}), but is strongly affected by the Pt layer.« less
  • B2-ordered Co{sub 2}FeAl films were synthesized using an ion beam deposition tool. A high degree of chemical ordering {approx}81.2% with a low damping parameter ({alpha}) less than 0.004 was obtained in a 50 nm thick film via rapid thermal annealing at 600 Degree-Sign C. The perpendicular magnetic anisotropy (PMA) was optimized in ultra thin Co{sub 2}FeAl films annealed at 350 Degree-Sign C without an external magnetic field. The reduced thickness and annealing temperature to achieve PMA introduced extrinsic factors thus increasing {alpha} significantly. However, the observed damping of Co{sub 2}FeAl films was still lower than that of Co{sub 60}Fe{sub 20}B{submore » 20} films prepared at the same thickness and annealing temperature.« less
  • Polycrystalline Fe{sub 0.4}Mn{sub 0.6} layers with the different thickness are deposited on 4-nm-thick single-crystalline Co{sub 2}FeAl layers, which are grown on GaAs (001) substrates at room temperature by molecular-beam epitaxy. Both the exchange bias and the in-plane magnetic anisotropies of the bilayers are strongly dependent on the thickness of the Fe{sub 0.4}Mn{sub 0.6} layer. The former is described using a granular level model. A modified Stoner-Wohlfarth model is used to explain the in-plane magnetic anisotropies observed at 5 K, while one possible reason for the magnetic anisotropies measured at 300 K is the complex interfacial magnetic properties proved by x-raymore » magnetic circular dichroism measurements.« less
  • Magnetic properties of Co{sub 40}Fe{sub 40}B{sub 20} (CoFeB) thin films sandwiched between Ta and MgAl{sub 2}O{sub 4} layers have been systematically studied. For as-grown state, Ta/CoFeB/MgAl{sub 2}O{sub 4} structures exhibit good perpendicular magnetic anisotropy (PMA) with interface anisotropy K{sub i} = 1.22 erg/cm{sup 2}, which further increases to 1.30 erg/cm{sup 2} after annealing, while MgAl{sub 2}O{sub 4}/CoFeB/Ta multilayer shows in-plane magnetic anisotropy and must be annealed in order to achieve PMA. For bottom CoFeB layer, the thickness window for PMA is from 0.6 to 1.0 nm, while that for top CoFeB layer is between 0.8 and 1.4 nm. Perpendicular magnetic tunnel junctions (p-MTJs) with a coremore » structure of CoFeB/MgAl{sub 2}O{sub 4}/CoFeB have also been fabricated and tunneling magnetoresistance ratio of about 36% at room temperature and 63% at low temperature have been obtained. The intrinsic excitations in the p-MTJs have been identified by inelastic electron-tunneling spectroscopy.« less
  • Magnetoresistance ratio up to 330% at room temperature (700% at 10 K) has been obtained in a spin-valve-type magnetic tunnel junction (MTJ) consisting of a full-Heusler alloy Co{sub 2}FeAl electrode and a MgO tunnel barrier fabricated on a single crystal MgO (001) substrate by sputtering method. The output voltage of the MTJ at one-half of the zero-bias value was found to be as high as 425 mV, which is the largest reported to date in MTJs using Heusler alloy electrodes. The present finding suggests that Co{sub 2}FeAl may be one of the most promising candidates for future spintronics devices applications.