FeRh with a meta-magnetic (from antiferromagnetic to ferromagnetic) phase transition at around 100°C has real potential for a range of applications including data storage media, magneto-electric devices, antiferromagnetic spintronics and magneto-calorics. Tuning the magnetic properties and transition temperature of FeRh is an important step in the path towards developing the flexibility needed for applications and has previously been achieved by doping with elements such as Pt, Pd and Ir. In this experiment we investigate the utility of light-ion irradiation to uniformly modify FeRh in a controlled manner. This would open new possibilities to laterally pattern single layer and multiple layer stacks creating devices on the sub-100 nm length scales with antiferromagnetic and ferromagnetic order in close physical proximity.