Control of the spatial distribution and crystal orientation of self-organized Au nanoparticles

Abstract

Ordered, two-dimensional, self-organized Au nanoparticles were fabricated using radiofrequency (RF) magnetron sputtering. The particles were uniformly spherical in shape and ultrafine in size (3-7 nm) and showed an ultrahigh density in the order of ∼10(12) inch(-2). A custom-developed sputtering apparatus that employs low sputtering power density and a minimized sputtering time (1 min) was used to markedly simplify the preparation conditions for Au nanoparticle fabrication. The spatial distribution of Au nanoparticles was rigorously controlled by placing a Ta interfacial layer between the Au nanoparticles and substrate as well as by post-annealing samples in an Ar atmosphere after the formation of Au nanoparticles. The interfacial layer and the post-annealing step caused approximately 40% of the Au nanoparticles on the substrate surface to orient in the (111) direction. This method was shown to produce ultrafine Au nanoparticles showing an ultrahigh surface density. The crystal orientation of the nanoparticles can be precisely controlled with respect to the substrate surface. Therefore, this technique promises to deliver tunable nanostructures for applications in the field of high-performance electronic devices.

Creation of Materials Based on Novel Principles Utilizing an Interaction between Magnetism and Electromagnetic Waves —Dynamic Permeability of Magnetoplumbite-structured Ferrite with an In-plane Magnetic Anisotropy Through the Controlled-particle Orientations—

“…1,2 In these studies, we attempted to precisely control the material structures to optimize the physical properties of the materials. [3][4][5][6] In this study, we report the dynamic magnetic properties of the materials in the GHzfrequency region induced by the interaction between magnetism of the materials and irradiated electromagnetic waves. High artificial control of the material structures is also discussed in this paper.…”