Co/Cu multilayer nanowires fabricated in an array using anodized aluminium oxide (AAO) template has been investigated. Experimental conditions are optimized to fabricate Co/Cu multilayer systems with fixed Cu and variable Co layer thicknesses. Magnetization reversal mode is found to depend on the Co layer thickness. A transition occurs from coherent rotation to a combination of coherent and curling rotation at around t(Co)=60 nm with increasing t(Co). The reversal modes have been investigated using the magnetic hysteresis loops measured at room temperature for Co/Cu nanowires placed at various angles between the directions of the nanowire axis and external fields using a vibrating sample magnetometer. The magnetic easy axis changes from the direction perpendicular to nanowires to that parallel to the nanowires at around t (Co)=60 nm, indicating a change in the magnetization reversal mode. The reversal mode for the nanowires with thin disk-shaped Co layers is of a coherent rotation type, while that for long rod-shaped Co layers can be explained by a combination of coherent rotation and a curling mode.
Bibliographical noteFunding Information:
This work was supported by the State Key Project of Fundamental Research of Ministry of Science and Technology (MOST, No. 2006CB932200 and 2009CB929203) and National Natural Science Foundation (NSFC, Grant 10874225, 50721001, and 60871048). X. F. Han thanks the partial support of the international joint projects of NSFC—The Royal Society (UK) and NSFC—Australia DEST and the partial support of K. C. Wong Education Foundation, Hong Kong. The author gratefully acknowledges the support of K. C. Wong Education Foundation, Hong Kong.
- Magnetization reversal