Effect of temperature on the exchange bias in naturally oxidized NixCo1-x (x=0.2) nanowires fabricated by electrochemical deposition technique

초록

NixCo1-x (x = 0.2) nanowires (with controlled diameter and length of similar to 120 nm and 30 mu m) have been fabricated by electrochemical deposition. Oxide layer of similar to 6 nm has been developed over a period of 400 days by natural oxidation of the wires. Temperature dependent magnetic analysis shows an increasing behavior of coercivity with decreasing temperature while field cooled hysteresis curves M(H) show exchange bias effect and vertical shift in magnetization below 150 K. This study demonstrates that the nanowires constitute core-shell cylindrical structure with ferromagnetic cores surrounded by antiferromagnetic oxide shells, which show blocking temperature of 150 K much lower than the Neel temperature of bulk Ni- and Co-oxide. (C) 2012 Elsevier B.V. All rights reserved.

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