  Rapid progress in information technologies has spurred the need for
innovative memory concepts, for which advanced data-processing methods and
tailor-made materials are required. Here we introduce a previously unexplored
nanoscale magnetic object: an analog magnetic vortex controlled by
electric-field-induced ion motion, termed magneto-ionic vortex or "vortion".
This state arises from paramagnetic FeCoN through voltage gating and gradual
N3-ion extraction within patterned nanodots. Unlike traditional vortex states,
vortions offer comprehensive analog adjustment of key properties such as
magnetization amplitude, nucleation/annihilation fields, or coercivity using
voltage as an energy-efficient tuning knob. This manipulation occurs
post-synthesis, obviating the need for energy-demanding methods like laser
pulses or spin-torque currents. By leveraging an overlooked aspect of
N3-magneto-ionics -- planar ion migration within nanodots -- precise control of
the magnetic layer's thickness is achieved, which enables reversible
transitions among paramagnetic, single-domain, and vortion states, offering
future prospects for analog computing, multi-state data storage, or
brain-inspired devices.
