21.15109/CONCORDA/83J6T0 Merkel, Dániel G.(1) Wigner Research Centre for Physics, 2) Centre for Energy Research)Lengyel, Attila(Wigner Research Centre for Physics)Nagy, Dénes Lajos0000-0002-6790-9505(Wigner Research Centre for Physics)Németh, Attila(Wigner Research Centre for Physics)Horváth, Zsolt E.(Centre for Energy Research)Bogdán, Csilla(Wigner Research Centre for Physics)Gracheva, Maria A.(Institute of Chemistry, Eötvös Loránd University)Hegedűs, Gergő(Wigner Research Centre for Physics)Sajti, Szilárd0000-0002-8748-8242(Wigner Research Centre for Physics)Radnóczi Z. György(Centre for Energy Research)Szilágyi Edit0000-0003-3210-0121(Wigner Research Centre for Physics) ARP 2021 The multilayer of approximate structure MgO(100)/[nFe51Rh49(63 Å)/57Fe51Rh49(46 Å)]10 deposited at 200 °C is primarily of paramagnetic A1 phase and is fully converted to the magnetic B2 phase by annealing at 300 °C for 60 min. Subsequent irradiation by 120 keV Ne+ ions turns the thin film completely to the paramagnetic A1 phase. Repeated annealing at 300 °C for 60 min results in 100% magnetic B2 phase, i.e. a process that appears to be reversible at least twice. The A1 → B2 transformation takes place without any plane-perpendicular diffusion while Ne+ irradiation results in significant interlayer mixing. Kutnyánszky, Anikó(Wigner Research Centre for Physics)