Title :
Local degradation of magnetic properties in magnetic thin films irradiated by Ga+ focused-ion-beams
Author :
Park, Chang-Min ; Bain, James A.
Author_Institution :
Dept. of Electr. & Comput. Eng., Carnegie Mellon Univ., Pittsburgh, PA, USA
fDate :
9/1/2002 12:00:00 AM
Abstract :
The magnetic properties of NiFe and FeCoN thin films were examined using Kerr microscopy after Ga+ focused-ion-beam (FIB) irradiation. Magneto-optic characterizations of 30 μm × 30 μm irradiated surface areas showed that the magnetization was reduced in approximately linear proportion to the Ga+ ion dose. Above an ion dose of approximately 0.6 nC/μm2 (3.8 × 1017 ions/cm2), little sign of the Kerr rotation could be found. The effect of the irradiation on the coercive force was also examined. Little effect of the beam on the coercivity of NiFe was seen, but an increase of coercivity was seen in FeCoN. The reduction of the Kerr rotation is attributed to magnetic moment loss caused by Ga implantation into the magnetic thin films. This loss has been quantified and is relevant to pole trimming for high-density magnetic recording heads.
Keywords :
Kerr magneto-optical effect; cobalt alloys; coercive force; ferromagnetic materials; focused ion beam technology; ion implantation; iron alloys; magnetic heads; magnetic moments; magnetic thin films; magnetisation; nickel alloys; 30 micron; FeCoN; FeCoN thin films; Ga; Ga implantation; Ga+ focused-ion-beam irradiation; Kerr microscopy; Kerr rotation; NiFe; NiFe thin films; coercive force; coercivity; high-density magnetic recording heads; magnetic moment loss; magnetic properties local degradation; magnetic thin films; magnetization; magneto-optic characterizations; pole trimming; surface areas; Coercive force; Degradation; Linear approximation; Magnetic films; Magnetic force microscopy; Magnetic losses; Magnetic moments; Magnetic properties; Magnetization; Magnetooptic effects;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2002.802681
