Jovana Jelić and Aleksa Denčevsk, two early-stage researchers and Ph.D. candidates, (Senzor Infiz, spin-off of Institute of Physics Belgrade, Serbia ) made a secondment to the University of Zaragoza/INMA in the framework of the Ultimate I project. The research lines of his group are directed at studying the surface properties of materials comprising both the surface physics and interfaces laboratories. The second included meetings with Spanish researchers, training, and measuring samples prepared in Serbia.