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In recent years magnetic skyrmions attracted great attention for the possibility to move them with low current density, their intrinsic stability and their robustness against defects and edge roughness compared to other magnetic textures. For applications, it is very important to be able to influence the behaviour of skyrmions locally. In this article, we present an evaluation on the effects of FIB Ga+ irradiation on skyrmion motion in W/CoFeB/MgO thin films. The influence of FIB irradiation is evaluated both, in terms of modification of the skyrmion Hall angle and the skyrmion velocity. An overview of the effects of the pulsing parameters on the skyrmion motion, shows low influence of the pulses rise-time and an external magnetic field. In addition the analysis after the irradiation shows that it influences notably the dynamics of skyrmions. In the irradiated zone the speed and angle of motion of these magnetic textures are strongly reduced. [ABSTRACT FROM AUTHOR]

• Skyrmionic bubble like structures are artificially created. • Pt/Co/Ir and Pt/Co/W films are optimized for skyrmionic bubble like structures. • Focused ion beam irradiation is used to generate skyrmionic bubble like structures. • Focused ion beam irradiation locates and stabilizes the bubbles. • The created spin-textures show high stability and can be tuned in size. Skyrmions provide high potential for low power magnetic computing. However, we are lacking methods for the controlled nucleation of skyrmions in magnetic thin films. We present a procedure for a controlled generation of skyrmionic bubble like structures (SBSs) at well-defined spots by focused ion beam (FIB) irradiation of magnetic multilayers. Series of Pt/Co/Ir and Pt/Co/W multilayers with interfacial Dzyaloshinskii-Moriya interaction (iDMI) were sputtered and optimized with respect to the domain structure and development under magnetic field. Applying an external magnetic field pulse of specific strength to a sample in both the demagnetized domain state and the uniform ferromagnetic state results in the condensation and nucleation of bubbles, respectively. In multilayer films, SBSs form randomly across the sample. To control the bubble nucleation, we irradiate the multilayer stacks with 50 kV Ga + ions to alter the magnetic properties along a hexagonal grid. We observe nucleation and geometric confinement of bubbles within the center of the hexagons. The lowered anisotropy in irradiated regions forms potential barriers which stabilizes the bubbles at room temperature and zero field. FIB tuned magnetic thin films give an exciting platform to investigate the behavior of SBSs in a confined state and to study the possibilities of controlled field- and current-driven motion. [ABSTRACT FROM AUTHOR]