Abstract
The magnetic behavior of antiferromagnetic nanostructures is usually dominated by a core-shell structure. Here we report on a magnetometry study on antiferromagnetic Co3 O4 nanostructures showing a magnetic decoupling of the core and its surface contribution below a critical structure size. Systems with sizes larger than 8 nm yield a common coupled magnetometric behavior of core and shell. However, for smaller structure sizes the core and shell contributions show independent magnetization signatures indicating a decoupling scenario.