Effect of Ga{sup +} irradiation in molecular-beam epitaxy grown Pt/Co/Pt thin films studied by magneto-optic spectroscopy

Journal Article · Wed May 07 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4861679· OSTI ID:22273898

Visnovsky, S. ^[1]; Wawro, A.; Baczewski, L. T. ^[2]; Mazalski, P.; Maziewski, A. ^[3]; Liedke, M. O. ^[4]; McCord, J. ^[5]; Fassbender, J. ^[6]

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1. Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 12116 Prague (Czech Republic)
2. Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa (Poland)
3. University of Bialystok, ul. Lipowa 41, 15-424 Bialystok (Poland)
4. Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Postfach 510119, 01314 Dresden (Germany)
5. Institute for Materials Science, Kiel University, Kaiserstr. 2, 24143 Kiel (Germany)
6. Institute of Ion Beam Physics and Material Research, Helmholtz-Zentrum Dresden-Rossendorf, Postfach 510119, 01314 Dresden (Germany)

In-depth profile changes induced by Ga{sup +} ion irradiation in Pt(5 nm)/Co(3.3 nm)/Pt(20 nm)/Mo(20 nm) sandwiches MBE grown on Al{sub 2}O{sub 3} substrates are deduced from complex magneto-optic polar Kerr effect (PMOKE) measurements at photon energies between 1 and 5 eV. The Ga{sup +} irradiation stimulates a redistribution of Pt and Co and leads to broadening of alloyed regions at Pt-Co and Co-Pt interfaces, which is evaluated using PMOKE spectra. The effect of four Ga{sup +} fluences D between zero and 6 × 10{sup 15} Ga{sup +}/cm{sup 2} was studied. The observed PMOKE azimuth rotation peak centered at 4.5 eV reaches the maximum of 0.42° at D = 1 × 10{sup 15} Ga{sup +}/cm{sup 2} and becomes thus enhanced by a factor of 3.2 with respect to that in the non-irradiated sample. At D = 6 × 10{sup 15} Ga{sup +}/cm{sup 2} the peak amplitude falls to 0.05°. To find the in-depth profile of Co concentration s in the sandwiches as a function of D, the PMOKE azimuth rotation and ellipticity spectra are compared with a multilayer model, where ideal flat interfaces are replaced by sequences of Co{sub s}Pt{sub 1−s} layers. The dependence on D is compared with that evaluated by simulations of the structural effects of ion irradiation. At the highest D, the irradiation produces an almost complete erosion of the top Pt and Co accompanied by mixing at the Pt-Mo interface.

• OSTI ID: 22273898
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 17; Conference: 55. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 14-18 Nov 2010; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTRA
ABSORPTION SPECTROSCOPY
ALUMINIUM OXIDES
COBALT
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
CONCENTRATION RATIO
GALLIUM IONS
INTERFACES
INTERMETALLIC COMPOUNDS
ION BEAMS
IRRADIATION
KERR EFFECT
LAYERS
MOLECULAR BEAM EPITAXY
PHOTONS
PHYSICAL RADIATION EFFECTS
PLATINUM
ROTATION
THIN FILMS