  A simple, reliable and field-free spin orbit torque (SOT)-induced
magnetization switching is a key ingredient for the development of the
electrical controllable spintronic devices. Recently, the SOT induced
deterministic switching of the CoPt single layer has attracts a lot of
interests, as it could simplifies the structure and add new flexibility in the
design of SOT devices, compared with the Ferromagnet/Heavy metal bilayer
counterparts. Unfortunately, under the field-free switching strategies used
nowadays, the switching of the CoPt layer is often partial, which sets a major
obstacle for the practical applications. In this study, by growing the CoPt on
vicinal substrates, we could achieve the full-scale (100% switching ratio)
field-free switching of the CoPt layer. We demonstrate that when grown on
vicinal substrates, the magnetic easy axis of the CoPt could be tilted from the
normal direction of the film plane; the strength of Dzyaloshinskii Moriya
interaction (DMI) would be also be tuned as well. Micromagnetic simulation
further reveal that the field-free switching stems from tilted magnetic
anisotropy induced by the vicinal substrate, while the enhancement of DMI help
reducing the critical switching current. In addition, we also found that the
vicinal substrates could also enhance the SOT efficiency. With such simple
structure, full-scale switching, tunable DMI and SOT efficiency, our results
provide a new knob for the design SOT-MRAM and future spintronic devices.
