Effect of He ions irradiation on anisotropy and magnetoresistance of (NiFe/Au/Co/Au) 10 multilayers

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 272; pp. 88 - 91
• Main Authors: Kuświk, P., Stobiecki, F., Szymański, B., Urbaniak, M., Falkowski, M., Jagielski, J., Mazalski, P.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2012
• Subjects: Anisotropy; Gold; Ion bombardment; Iron; Magnetic multilayers; Magnetic properties; Magnetoresistance; Multilayers; Nickel; Perpendicular magnetic anisotropy; Reduction; Perpendicular magnetic anisotropy; Magnetic multilayers; Ion bombardment
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2011.01.038

Sputter deposited ( Ni 80 Fe 20 - 2 nm / Au- 2 nm / Co- t Co / Au- 2 nm ) 10 multilayers are characterized by alternating in-plane ( Ni 80 Fe 20 ) and out-of-plane (for Co thickness in the range 0.3 < t Co < 1.2 nm ) magnetic anisotropy. The magnetic properties of the samples, before and after ion bombardment, were characterized by magnetometric and magnetoresistive measurements. The irradiation process was performed with fluences of 30 keV He + ions varied in the range 10 13 ⩽ D ⩽ 3 × 10 16 He + / cm 2 . We report that for fluences in the range between 10 15 and 10 16 He + / cm 2 the effective (perpendicular) anisotropy of the Co layer decreases noticeably. The origin of the effect is related to a reduction in the surface anisotropy thus to interfaces modification. As a consequence strong reduction of magnetoresistance was also observed.