  Despite the composition close to glassy forming alloys, face centered cubic
(FCC) Co81.8Si9.1B9.1, designed based on Co9B atomic cluster (polyhedral), are
synthesized as singlephase ribbons successfully. These ribbons, with grain
sizes of ca. 92 nm, show supreme ductility and strong orientation along (111),
which couples with shape anisotropy leading to high magnetocrystalline
anisotropy comparable to Co rich Co-Pt nanoscale thin films, with a coercivity
of 430 Oe and squareness of 0.82 at room temperature. The stability and
magnetic behaviors of the phase are discussed based on experimental electronic
structure. This work not only develops low cost Co-based materials for hard
magnetic applications, but also extends the atomic cluster model developed for
amorphous alloys into the design of new crystalline materials.
