Influence of ion implantation on the magnetic properties of thin FeCo films

Journal Article · Thu Mar 31 23:00:00 EST 2005 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1875737· OSTI ID:20668285

Gupta, Ratnesh; Han, K -H; Lieb, K P; Mueller, G A; Schaaf, P; Zhang, K ^[1]

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1. II. Physikalisches Institut and SFB 602, Universitaet Goettingen, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany)

Modifications of 73-nm-thick polycrystalline FeCo films by magnetic-field-assisted implantation of Ne, Xe, and Au ions have been investigated. For magnetic characterization, the longitudinal magneto-optic Kerr effect and magnetic force microscopy (MFM) in the remanent state have been used, while structural information has been gained from glancing-angle x-ray diffraction and Rutherford backscattering spectroscopy. The irradiated films show a soft-magnetic behavior with large magnetic anisotropy. The Ne ions initially induce an increasing coercivity, possibly due to radiation defects accumulated during the ion implantation, while higher Ne fluences anneal out the defects and reduce the coercivity. For the heavy ions the deposited energy density is high enough to reduce the coercivity at small fluences and then to increase it slightly for increasing fluence. Correlations between the magnetic anisotropy, coercivity and the ion species and fluence have been established. The MFM pictures feature the largest changes in the case of Au ions. The magnetic anisotropy reflects the interplay between magnetocrystalline and magnetostrictive forces. For heavier ions and large fluences, the direction of the in-plane magnetic easy axis follows the orientation of the external magnetic field present during implantation.

• OSTI ID: 20668285
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 7 Vol. 97; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANISOTROPY
ATOMIC FORCE MICROSCOPY
BINARY ALLOY SYSTEMS
COBALT ALLOYS
COERCIVE FORCE
ENERGY DENSITY
FERROMAGNETIC MATERIALS
GOLD IONS
HEAVY IONS
ION IMPLANTATION
IRON ALLOYS
KERR EFFECT
MAGNETIC FIELDS
MAGNETO-OPTICAL EFFECTS
MAGNETOSTRICTION
NEON IONS
RUTHERFORD BACKSCATTERING SPECTROSCOPY
THIN FILMS
X-RAY DIFFRACTION
XENON IONS