• 文献标题:   Magnetic properties of Dy nano-islands on graphene
  • 文献类型:   Article
  • 作  者:   ANDERSON NA, ZHANG Q, HUPALO M, ROSENBERG RA, FREELAND JW, TRINGIDES MC, VAKNIN D
  • 作者关键词:   dysprosium, nanoisland, xmcd, stm
  • 出版物名称:   JOURNAL OF MAGNETISM MAGNETIC MATERIALS
  • ISSN:   0304-8853 EI 1873-4766
  • 通讯作者地址:   Iowa State Univ
  • 被引频次:   3
  • DOI:   10.1016/j.jmmm.2017.04.007
  • 出版年:   2017

▎ 摘  要

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,M-5 XMCD spectra at low temperatures (T = 15 K) as a function of magnetic field assuming Dy3+ (spin configuration H-6(15/ 2)) indicate that the projection of the magnetic moment along an applied magnetic field of 5 T is 3.5(3) mu(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 similar to 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. (C) 2017 Elsevier B.V. All rights reserved.