AF proximity effect in Co NPs

High Temperature Magnetic Stabilization of Cobalt Nanoparticles by an Antiferromagnetic Proximity Effect.
José A. De Toro, Daniel P. Marques, Pablo Muñiz, Vassil Skumryev, Jordi Sort, Dominique Givord, and Josep Nogués

Phys. Rev. Lett. 115, 057201 (2015)

(a) Schematic representation of the Co/CoO−NiO sample. (b) Field-cooled hysteresis loops of the Co/CoO−NiO samples (S series) at 10 K. Shown in the inset is the 10-K hysteresis loop of R80. (c) Field-cooled hysteresis loops of the same samples at 300 K. Shown in the inset are the same loops up to higher fields.