Abstract
The magnetic characteristics of iron nanoparticles embedded in an alumina thin film matrix have
been studied as a function of spacer layer thickness. Alumina as well as iron nanoparticles were
deposited in a multilayered geometry using sequential pulsed laser deposition. The role of spacer
layer thickness was investigated by making layered thin film composites with three different spacer
layer thicknesses 6, 12, and 18 nm with fixed iron particle size of 13 nm. Intralayer magnetic
interactions being the same in each sample, the variation in coercivity and saturation magnetization
is attributed to thickness dependent interlayer magnetic interactions of three types: exchange, strong
dipolar, and weak dipolar. A thin film composite multilayer structure offers a continuously tunable
strength of interparticle dipole-dipole interaction and is thus well suited for studies of the influence
of interaction on the magnetic properties of small magnetic particle systems.