Oriented, single domain Fe nanoparticle layers in single crystal yttria-stabilized zirconia

To create an ensemble of oriented, single crystal particles of iron, Fe ions were implanted into the near-surface region of single crystal yttria-stabilized zirconia (YSZ). With thermal processing, the implanted species precipitated to form faceted, predominantly single domain ferromagnetic nanoparticles. The YSZ substrate isolates, protects, and crystallographically textures the nanoparticles, creating a magnetically anisotropic layer. Experimental studies of the magnetization M(H,T) at various orientations of the applied field H show a major distinction only between H || nˆ (hard direction) and H ⊥ nˆ (easy direction) where nˆ is the surface normal; there is little angular variation within the plane. This feature and the behavior of the orientationally dependent coercive field H_c and magnetic remanence M_r are attributed to magnetostatic interactions between the particles. Non-interacting single-domain particles should show a Stoner-Wohlfarth-like behavior that is poorly approximated in this far-from-close-packed system