  The Technical Committee of the IEEE Magnetics Society has selected 7 research
topics to develop their roadmaps, where major developments should be listed
alongside expected timelines; (i) hard disk drives, (ii) magnetic random access
memories, (iii) domain-wall devices, (iv) permanent magnets, (v) sensors and
actuators, (vi) magnetic materials and (vii) organic devices. Among them,
magnetic materials for spintronic devices have been surveyed as the first
exercise. In this roadmap exercise, we have targeted magnetic tunnel and
spin-valve junctions as spintronic devices. These can be used for example as a
cell for a magnetic random access memory and spin-torque oscillator in their
vertical form as well as a spin transistor and a spin Hall device in their
lateral form. In these devices, the critical role of magnetic materials is to
inject spin-polarised electrons efficiently into a non-magnet. We have
accordingly identified 2 key properties to be achieved by developing new
magnetic materials for future spintronic devices: (1) Half-metallicity at room
temperature (RT); (2) Perpendicular anisotropy in nano-scale devices at RT. For
the first property, 5 major magnetic materials are selected for their
evaluation for future magnetic/spintronic device applications: Heusler alloys,
ferrites, rutiles, perovskites and dilute magnetic semiconductors. These alloys
have been reported or predicted to be half-metallic ferromagnets at RT. They
possess a bandgap at the Fermi level EF only for its minority spins, achieving
100% spin polarisation at EF. We have also evaluated L10-alloys and
D022-Mn-alloys for the development of a perpendicularly anisotropic ferromagnet
with large spin polarisation. We have listed several key milestones for each
material on their functionality improvements, property achievements, device
implementations and interdisciplinary applications within 35 years time scale.
