The aim of the experiment is to study the contributions of the pinned and unpinned antiferromagnetic (AF) domains to the exchange bias (EB) occurring at the interface of the NiO(111)/EuO(001) system using specular polarised neutron reflectivity (PNR). D17 with a polarised monochromatic beam is the ideal instrument for this experiment, because EB is an interface effect and it can only be measured with a depth-sensitive technique. Furthermore, it is well known that naturally occurring Eu due to the large proportion (~47.86%) of the isotope 151Eu shows a strong energy dependence of the coherent scattering length [1].