Fabrication of single-dot planar nano-devices and the application to the exchange bias characterization in nano-pillar devices

Abstract

Single dot [Co/Pd]5/FeMn nano-pillar devices with split nano-contacts are fabricated down to 150 × 150 nm2 dimensions, to understand the effects of nano-patterning on perpendicular exchange bias (PEB) characteristics. Using extraordinary Hall effect measurements, magnetic force microscopy, and numerical calculations, it is shown that the exchange bias field initially increases from the thin-film value, with decreasing dimensions down to a critical dimension below, which it again reduces. The PEB characteristics of the nano-pillar devices are found to be influenced by changes to the ferromagnetic (FM) layer anisotropy, exchange coupling between ferromagnetic and antiferromagnetic layers, in addition to edge effects caused by the fabrication process. © 2012 American Institute of Physics.