Article ID Journal Published Year Pages File Type
1672120 Thin Solid Films 2008 5 Pages PDF
Abstract

By controlling the early stages of thin film growth during laser ablation (i.e. Volmer–Weber type growth), we have synthesized magnetic nanocomposites consisting of nickel (Ni) nanoparticulates in multiple layers of yttria stabilized zirconia. The magnetic properties are a strong function of the nickel particle size, showing a clear transition from superparamagnetic to ferromagnetic characteristics. The coercivity at 300 K varies from 0 to nearly 13 kA m− 1 (∼ 160 Oe) as the laser ablation time is increased. By applying the Scherrer formula to X-ray diffraction patterns, we estimated the average size of the Ni nanoclusters to be < 5 – 20 nm for the four samples. For the superparamagnetic sample, a blocking temperature of ∼ 100 K has been estimated by applying a field much lower than the saturation field and measuring magnetization versus temperature in field cooled and zero field cooled modes.

Related Topics
Physical Sciences and Engineering Materials Science Nanotechnology
Authors
, , , , ,