  We show that magnetic skyrmions can be stabilized at room temperature in
continuous Ir/Co/Pt multilayers on SiO2/Si substrate without prior application
of electric current or magnetic field. While decreasing the Co thickness,
tuning of the magnetic anisotropy gives rise to a transition from worm-like
domain patterns to long and separate stripes. The skyrmions are clearly imaged
in both states using Magnetic Force Microscopy. The density of skyrmions can be
significantly enhanced after applying the in-plane field procedure. In
addition, we have investigated the phase diagram of a sample deposited in the
same run, but onto a SiNx membrane using Lorentz transmission electron
microscopy. Interestingly, this sample shows a different behaviour as function
of magnetic field hinting to the influence of strain on the phase diagram of
skyrmions in thin film multilayers. Our results provide means to manipulate
skyrmion, further allowing for optimized engineering of skyrmion-based devices.
