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Magnetic anisotropy of ultrathin cobalt films on Pt(111) investigated with x-ray diffraction: Effect of atomic mixing at the interface

Robach, O; Quiros, C; Steadman, P; Peters, KF; Lundgren, Edvin LU ; Alvarez, J; Isern, H and Ferrer, S (2002) In Physical Review B (Condensed Matter and Materials Physics) 65(5).
Abstract
With standard and resonant x-ray magnetic diffraction we investigate the magnetic properties of Pt atoms in a Co/Pt(111) system. It is shown, that, depending on the thickness of the Co films, the magnetic anisotropy as monitored by the Pt magnetism changes from perpendicular to parallel, mimicking the behavior of the Co overlayer. Adsorption of carbon monoxide on very thin films has been found to change the easy magnetization axis. Moreover, the critical film thickness for the flipping of the easy direction of magnetization depends markedly on the growth temperature even in the vicinities of 300 K, where bulk alloying does not occur. A brief annealing to similar to375 K of a parallel Co film suffices to reverse its easy direction to... (More)
With standard and resonant x-ray magnetic diffraction we investigate the magnetic properties of Pt atoms in a Co/Pt(111) system. It is shown, that, depending on the thickness of the Co films, the magnetic anisotropy as monitored by the Pt magnetism changes from perpendicular to parallel, mimicking the behavior of the Co overlayer. Adsorption of carbon monoxide on very thin films has been found to change the easy magnetization axis. Moreover, the critical film thickness for the flipping of the easy direction of magnetization depends markedly on the growth temperature even in the vicinities of 300 K, where bulk alloying does not occur. A brief annealing to similar to375 K of a parallel Co film suffices to reverse its easy direction to perpendicular. By analyzing the magnetic crystal truncation rods of the Pt surface, it is concluded that the change of anisotropy is due to site exchange between interfacial Co and Pt atoms. The site exchange which affects up to 4% of the interface atoms has been related to previous scanning tunneling microscopy findings on the same system. Comparison of magneto-optical and x-ray magnetic diffraction measurements on the same film show that the responses to the externally applied field are not identical. A possible explanation is suggested. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B (Condensed Matter and Materials Physics)
volume
65
issue
5
publisher
American Physical Society
external identifiers
  • wos:000173647000070
  • scopus:0036468212
ISSN
1098-0121
DOI
10.1103/PhysRevB.65.054423
language
English
LU publication?
yes
id
bd1ad439-0bd6-41b7-a706-18b880a0a632 (old id 343654)
date added to LUP
2007-11-12 11:27:29
date last changed
2017-09-10 04:30:51
@article{bd1ad439-0bd6-41b7-a706-18b880a0a632,
  abstract     = {With standard and resonant x-ray magnetic diffraction we investigate the magnetic properties of Pt atoms in a Co/Pt(111) system. It is shown, that, depending on the thickness of the Co films, the magnetic anisotropy as monitored by the Pt magnetism changes from perpendicular to parallel, mimicking the behavior of the Co overlayer. Adsorption of carbon monoxide on very thin films has been found to change the easy magnetization axis. Moreover, the critical film thickness for the flipping of the easy direction of magnetization depends markedly on the growth temperature even in the vicinities of 300 K, where bulk alloying does not occur. A brief annealing to similar to375 K of a parallel Co film suffices to reverse its easy direction to perpendicular. By analyzing the magnetic crystal truncation rods of the Pt surface, it is concluded that the change of anisotropy is due to site exchange between interfacial Co and Pt atoms. The site exchange which affects up to 4% of the interface atoms has been related to previous scanning tunneling microscopy findings on the same system. Comparison of magneto-optical and x-ray magnetic diffraction measurements on the same film show that the responses to the externally applied field are not identical. A possible explanation is suggested.},
  author       = {Robach, O and Quiros, C and Steadman, P and Peters, KF and Lundgren, Edvin and Alvarez, J and Isern, H and Ferrer, S},
  issn         = {1098-0121},
  language     = {eng},
  number       = {5},
  publisher    = {American Physical Society},
  series       = {Physical Review B (Condensed Matter and Materials Physics)},
  title        = {Magnetic anisotropy of ultrathin cobalt films on Pt(111) investigated with x-ray diffraction: Effect of atomic mixing at the interface},
  url          = {http://dx.doi.org/10.1103/PhysRevB.65.054423},
  volume       = {65},
  year         = {2002},
}