  Magnetic skyrmions form in chiral multilayers from the shrinking or fission
of elongated stripe textures. Here we report an experimental and theoretical
study of the temperature dependence of this stripe-to-skyrmion transition in
Co/Pt-based multilayers. Field-reversal magnetometry and Lorentz microscopy
experiments over 100 - 350 K establish the increased efficacy of
stripe-to-skyrmion fission at higher temperatures - driven primarily by the
thermal evolution of key magnetic interactions - thereby enhancing skyrmion
density. Atomistic calculations elucidate that the energy barrier to fission
governs the thermodynamics of the skyrmion formation. Our results establish a
mechanistic picture of the stripe-to-skyrmion transition and advance the use of
thermal knobs for efficient skyrmion generation.
