Control of magnetic properties of MnBi and MnBiCu thin films by Kr{sup +} ion irradiation

Journal Article · Sun Apr 01 00:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3675981· OSTI ID:22038925

Qianqian, Xu; Kanbara, Ryutarou; Kato, Takeshi; Iwata, Satoshi ^[1]; Tsunashima, Shigeru ^[2]

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1. Department of Quantum Engineering, Nagoya University Furo-cho, Chikusa-ku, Nagoya, 464-8603 (Japan)
2. Department of Research, Nagoya Industrial Science Research Institute, 1-13 Yotsuya-dori, Chikusa-ku, Nagoya 460-0819 (Japan)

Mn{sub 52}Bi{sub 48} (15 nm) and Mn{sub 54}Bi{sub 24}Cu{sub 21} (15 nm) thin films were prepared by the magnetron sputtering and vacuum annealing at 350 deg. C, and the variations of their structures and magnetic properties with 30 keV Kr{sup +} ion irradiation were studied. The MnBi and MnBiCu films exhibited saturation magnetizations M{sub s} of 180 emu/cc and 210 emu/cc, the coercivities H{sub c} of 10 kOe and 3.4 kOe, respectively. The M{sub s} and H{sub c} of the MnBi abruptly vanished by the irradiation of ion dose at 3 x 10{sup 14} ions/cm{sup 2}, while those of the MnBiCu film gradually decreased with increasing the ion dose and became zero at 5 x 10{sup 13} ions/cm{sup 2}. The different trend on the ion irradiation between MnBi and MnBiCu films is understood by the surface structure of the film, i.e., the MnBi has convex islands on its surface, which protect the underneath NiAs-type MnBi from the irradiation, while the MnBiCu has rather flat surface, and its crystal structure was uniformly modified by the irradiation. From the surface flatness and the uniformity of the MnBiCu film, as well as the low annealing temperature of 350 deg. C, it was concluded that the MnBiCu film is one of the attractive materials for high-density ion irradiation bit patterned media.

• OSTI ID: 22038925
• Journal Information: Journal of Applied Physics, Vol. 111, Issue 7; Conference: 55. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 14-18 Nov 2010; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
BISMUTH ALLOYS
COERCIVE FORCE
COPPER ALLOYS
CRYSTAL STRUCTURE
DEPOSITION
EPITAXY
ION BEAMS
IRRADIATION
KEV RANGE
KRYPTON IONS
MAGNETIC PROPERTIES
MAGNETIZATION
MANGANESE ALLOYS
RADIATION EFFECTS
SPUTTERING
THIN FILMS