Control of exchange bias by modifying the antiferromagnet and ferromagnet-antiferromagnet interface

This study focuses on the control of exchange bias due to the modification of antiferromagnet and ferromagnet-antiferromagnet interface. Thin films of Ni-NiO were developed by thermal evaporation and subsequent annealing to realize a ferromagnet-antiferromagnet interface in which NiO is an antiferromagnet. The thickness and composition of individual magnetic layers were measured and optimized using Rutherford backscattering spectrometry. Ion implantation in these films is carried out using 100 keV and 200 keV Cu ions such that ions get deposited in the NiO layer and at Ni-NiO interface. This method offers a unique possibility to study the influence of different magnetic layers/interface on exchange bias. The experimental results show an initial enhancement followed by a decrease in exchange bias with ion fluence using 100 keV Cu ions. Interestingly, modifications in exchange bias are found to be more prominent in films where Cu ions are implanted in the NiO layer rather than in the Ni-NiO interface.