Abstract
We have shown that the magnetic properties of nanoparticles may be tuned from superparamagnetic
to ferromagnetic by changing the substrate or thin film matrix in which they are embedded. Nickel
nanoparticles were embedded into alumina, titanium nitride, and cerium oxide matrices on both
silicon and sapphire substrates via pulsed laser deposition. The laser ablation time on the nickel
target was kept constant. Only nickel nanoparticles in cerium oxide showed characteristics of
ferromagnetism room temperature coercivity and remanence. Ni nanoparticles, in either alumina
or titanium nitride, possessed blocking temperatures below 200 K. Detailed scanning transmission
electron microscopy analysis has been conducted on the samples embedded into cerium oxide on
both substrates and related to the magnetic data.