Magnetic enhancement and nitriding process of Fe atomic layers on Si 111-7 × 7-CH3OH surface

•Linear Fe clusters were formed on Si (111)-7×7-CH3OH surface, without forming Fe-Si bonds.•Under the influence of quasi potential energy, Fe clusters are nitrided at room temperature.•Forming the quasi potential surface in a more precise mode, the nitriding efficiency is improved greatly.•Focusing on magnetic performance, the formation of linear structure becomes more controllable.•New linear iron-nitride clusters would maintain good structural stability and oxidation resistance.