Publication Date:
2016-10-13
Description:
To investigate the possible sources of the switching field distribution in bit-patterned media, we applied a scanning hard-X-ray nanoprobe technique based on X-ray magnetic circular dichroism spectroscopy to an array of Co-Pt dots with the typical diameters of 200 nm. Element-specific magnetization curves at the Pt L 3 edge were measured for individual dots isolated from each other, and the magnetization switching field (coercivity) values were determined for more than 100 individual dots. To assess the effect of dot diameters as a possible source of switching field distribution, a statistical analysis of the coercivity values and dot diameters measured for many dots was performed. The resulting switching field distribution had a mean of ⟨ H SW ⟩ = 1.80 kOe and a standard deviation of σH SW = 0.64 kOe. The relative deviation of σ H SW / ⟨ H SW ⟩ = 36 % was not in good agreement with the relative dispersion in a dot diameter of σ D / ⟨ D ⟩ = 2.7 % , and no clear correlation between the coercivity and dot diameter was observed. These results may suggest other possible sources of switching field distribution than dot diameter, such as dispersion in the c -axis orientation and in magnetocrystalline anisotropy.
Print ISSN:
0021-8979
Electronic ISSN:
1089-7550
Topics:
Physics
