Exchange bias effect in Ni₈₀Fe₂₀/CoO bi-component nanowires

Information Storage Materials Laboratory, Department of Electrical and Computer Engineering, National University of Singapore - Singapore-117576, Singapore

^(a) eleaao@nus.edu.sg (corresponding author)

Received: 11 June 2014
Accepted: 12 September 2014

Abstract

We investigate the magnetic and transport behavior of exchange biased Ni₈₀Fe₂₀(Py)/CoO bi-component nanowires (NWs) consisting of Py NWs with top surface fully or partially covered with CoO and lateral exchange coupled Py/CoO structure. The exchange bias field and magnetoresistance (MR) behavior of the bi-component NWs are found to be markedly dependent on the Py/CoO interface area. We observed that when the Py/CoO interface area is reduced to half, the exchange bias field decreases significantly due to the reduced interfacial anisotropy. We found that the degree of asymmetry of the ascending and descending MR branches is very sensitive to the Py/CoO interface area. For lateral exchange coupled Py/CoO structure, we observed a weak exchange bias effect below 50 K due to a much smaller effective interfacial anisotropy.