skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Magnetic properties of Dy nano-islands on graphene

Abstract

Here, we have determined the magnetic properties of epitaxially grown Dy islands on graphene/SiC(0001) that are passivated by a gold film (deposited in the ultra-high vacuum growth chamber) for ex-situ X-ray magnetic circular dichroism (XMCD). Our sum-rule analysis of the Dy M 4,5 XMCD spectra at low temperatures ( T = 15 K) as a function of magnetic field assuming Dy 3+ (spin configuration 6 H 15/2) indicate that the projection of the magnetic moment along an applied magnetic field of 5 T is 3.5(3) μ B. Temperature dependence of the magnetic moment (extracted from the M 5 XMCD spectra) shows an onset of a change in magnetic moment at about 175 K in proximity of the transition from paramagnetic to helical magnetic structure at T H = 179 K in bulk Dy. No feature at the vicinity of the ferromagnetic transition of hcp bulk Dy at T c = 88 K is observed. However, below ~130 K, the inverse magnetic moment (extracted from the XMCD) is linear in temperature as commonly expected from a paramagnetic system suggesting different behavior of Dy nano-island than bulk Dy.

Authors:
 [1];  [1];  [1];  [2];  [2];  [1];  [1]
  1. Ames Lab. and Iowa State Univ., Ames, IA (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
Publication Date:
Research Org.:
Ames Lab., Ames, IA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1371900
Alternate Identifier(s):
OSTI ID: 1415891
Report Number(s):
IS-J-9343
Journal ID: ISSN 0304-8853; PII: S0304885316328591
Grant/Contract Number:
AC02-07CH11358; AC02-06CH11357
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Magnetism and Magnetic Materials
Additional Journal Information:
Journal Volume: 435; Journal Issue: C; Journal ID: ISSN 0304-8853
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; dysprosium nano-islands; XMCD; STM

Citation Formats

Anderson, Nathaniel A., Zhang, Qiang, Hupalo, Myron, Rosenberg, Richard A., Freeland, John W., Tringides, Michael C., and Vaknin, David. Magnetic properties of Dy nano-islands on graphene. United States: N. p., 2017. Web. doi:10.1016/j.jmmm.2017.04.007.
Anderson, Nathaniel A., Zhang, Qiang, Hupalo, Myron, Rosenberg, Richard A., Freeland, John W., Tringides, Michael C., & Vaknin, David. Magnetic properties of Dy nano-islands on graphene. United States. doi:10.1016/j.jmmm.2017.04.007.
Anderson, Nathaniel A., Zhang, Qiang, Hupalo, Myron, Rosenberg, Richard A., Freeland, John W., Tringides, Michael C., and Vaknin, David. Fri . "Magnetic properties of Dy nano-islands on graphene". United States. doi:10.1016/j.jmmm.2017.04.007. https://www.osti.gov/servlets/purl/1371900.
@article{osti_1371900,
title = {Magnetic properties of Dy nano-islands on graphene},
author = {Anderson, Nathaniel A. and Zhang, Qiang and Hupalo, Myron and Rosenberg, Richard A. and Freeland, John W. and Tringides, Michael C. and Vaknin, David},
abstractNote = {Here, we have determined the magnetic properties of epitaxially grown Dy islands on graphene/SiC(0001) that are passivated by a gold film (deposited in the ultra-high vacuum growth chamber) for ex-situ X-ray magnetic circular dichroism (XMCD). Our sum-rule analysis of the Dy M4,5 XMCD spectra at low temperatures (T = 15 K) as a function of magnetic field assuming Dy3+ (spin configuration 6H15/2) indicate that the projection of the magnetic moment along an applied magnetic field of 5 T is 3.5(3) μB. Temperature dependence of the magnetic moment (extracted from the M5 XMCD spectra) shows an onset of a change in magnetic moment at about 175 K in proximity of the transition from paramagnetic to helical magnetic structure at TH = 179 K in bulk Dy. No feature at the vicinity of the ferromagnetic transition of hcp bulk Dy at Tc = 88 K is observed. However, below ~130 K, the inverse magnetic moment (extracted from the XMCD) is linear in temperature as commonly expected from a paramagnetic system suggesting different behavior of Dy nano-island than bulk Dy.},
doi = {10.1016/j.jmmm.2017.04.007},
journal = {Journal of Magnetism and Magnetic Materials},
number = C,
volume = 435,
place = {United States},
year = {Fri Apr 07 00:00:00 EDT 2017},
month = {Fri Apr 07 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 2works
Citation information provided by
Web of Science

Save / Share:
  • Cited by 2
  • X-ray magnetic circular dichroism (XMCD) measurements of iron nano-islands grown on graphene and covered with a Au film for passivation reveal that the oxidation through defects in the Au film spontaneously leads to the formation of magnetite nano-particles (i.e, Fe 3O 4). The Fe nano-islands (20 and 75 monolayers; MLs) are grown on epitaxial graphene formed by thermally annealing 6HSiC( 0001) and subsequently covered, in the growth chamber, with nominal 20 layers of Au. Our X-ray absorption spectroscopy and XMCD measurements at applied magnetic fields show that the thin film (20 ML) is totally converted to magnetite whereas the thickermore » lm (75 ML) exhibits properties of magnetite but also those of pure metallic iron. Temperature dependence of the XMCD signal (of both samples) shows a clear transition at T V ≈ 120 K consistent with the Verwey transition of bulk magnetite. These results have implications on the synthesis of magnetite nano-crystals and also on their regular arrangements on functional substrates such as graphene.« less
  • To obtain an engineered surface for deposition of high-Tc superconductors, nanoscale modulations of the surface of the underlying LaMnO3 (LMO) cap layer is a potential source for generating microstructural defects in YBa2Cu3O7- (YBCO) films. These defects may improve the flux-pinning and consequently increase the critical current density, Jc. To provide such nanoscale modulation via a practical and scalable process, tantalum (Ta) and palladium (Pd) nano-islands were deposited using dc-magnetron sputtering on the surface of the cap layer of commercial metal tape templates for second-generation wires. The size and density of these nano-islands can be controlled by changing sputtering conditions suchmore » as the power and deposition time. Compared to the reference sample grown on an untreated LMO cap layer, the YBCO films grown on the LMO cap layers with Ta or Pd nano-islands exhibited improved in-field Jc performance. Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM) were used to assess the evolving size and density of the nano-islands.« less
  • The magnetic properties of Dy{sub 2}Fe{sub 17} and Dy{sub 2}Fe{sub 17}C have been reported. The expansion of the lattice and increase of Curie temperature {ital T}{sub {ital c}} and magnetization {ital M} have been found for Dy{sub 2}Fe{sub 17}C, and compared with Dy{sub 2}Fe{sub 17}. From the study of {sup 57}Fe Mossbauer spectra, we found that the average hyperfine field of Dy{sub 2}Fe{sub 17}C is about 5 T larger than that of Dy{sub 2}Fe{sub 17}. The isomer shift of the 4{ital f} site is smaller for Dy{sub 2}Fe{sub 17}C compared with Dy{sub 2}Fe{sub 17}.
  • A new family of mixed lanthanide(III) and iron(III) oxo-phosphate phases, Rb{sub 7}LnFe{sub 6}O{sub 2}(PO{sub 4}){sub 8} (Ln=Sm 1, Eu 2, Gd 3, Dy 4), was isolated by using a high-temperature, solid-state method in molten-salt media. The X-ray single-crystal structure analysis shows that these isomorphic derivatives crystallize in a triclinic space group P-1 (no. 2); Z=1. The 3-D framework of these 3d-4f oxo-phosphates are comprised of LnO{sub 6} octahedral, FeO{sub 5} trigonal bipyramidal (tbp), and {mu}{sub 3}-oxo [Fe{sub 4}O{sub 18}] tetrameric units interconnected through PO{sub 4} tetrahedra. The preliminary results of the temperature-dependent magnetic susceptibility measurements for selected compounds (1, 3,more » 4) reveal antiferromagnetic-like behavior. 1 shows a weak antiferromagnetric ordering at T{sub N}={approx}7 K while others show little evidence of long-range magnetic order down to 2 K. All three compounds have measured magnetic moments significantly smaller than the expected values. - Graphical abstract: The extended framework is described by the connectivity of three distinct types of paramagnetic units. The temperature-dependent, lower than expected effective magnetic moments are reported. Highlights: Black-Right-Pointing-Pointer A new family of mixed lanthanide(III) and iron(III) oxo-phosphates is isolated. Black-Right-Pointing-Pointer Features PO{sub 4}-linked paramagnetic units of LnO{sub 6}, FeO{sub 5}, and {mu}{sub 3}-oxo [Fe{sub 4}O{sub 18}]. Black-Right-Pointing-Pointer Sm-derivative orders at T{sub N}{approx}7 K while Gd- and Dy-derivatives show absence of order.« less