Structural Variation in Ag–Co Nanostructures Embedded in TiO2 Thin Films Fabricated by Pulsed Laser Deposition

Abstract

We investigated the structural variation of Ag–Co nanostructures in AgxCo5(TiO2)95 nanocomposite films with varying pulsed laser deposition conditions. The shape, size, and distribution of the nanostructures were significantly affected by the Ag content (x) and the substrate temperature. Ag–Co nanomatch-like structures appeared only at a specific condition and changed from rod-like to spherical with increasing x. A broad peak owing to Ag local-surface plasmon resonance was observed in the absorption spectra, which systematically shifted to longer wavelengths with increasing x.

Photoelectrochemical Behavior of Self-Assembled Ag/Co Plasmonic Nanostructures Capped with TiO2

“…The typical film thickness of the top layer and the seed layer are ∼23 and ∼2 nm, respectively. The figure demonstrates the characteristic “nanomatch”-like structures composed of Co nanospheres at the bottom and Ag nanorods at the top, similar to those observed in the Ag–Co–TiO 2 film on the LaSrAlO 4 insulate substrate . The Ag–Co nanomatch-like structures are located in the film matrix ∼5 nm apart from the seed layer.…”

“…Each Ag nanorod with a dimension of ∼5 nm in diameter and ∼10 nm in length grows from a Co nanosphere toward the film surface. The formation mechanism of the Ag–Co nanostructures was reported previously . Tiny Co nanoclusters on the film surface prevent the Ag nanorods from exposure to air.…”

“…Each Ag−Co nanostructure has a characteristic nanomatch-like shape composed of a Co nanosphere and a Ag nanorod. Suprisingly, this compoiste film showed clear LSPR of the Ag nanorods in the visible wavelength region, 25 and moreover, the plasmon resonance spectrum was maintained even 6 months after film deposition. The Ag−Co nanostructure encapsuled in a TiO 2 matrix was also stable in various solvents, including water, ethanol, and acetone.…”

“…The figure demonstrates the characteristic "nanomatch"-like structures composed of Co nanospheres at the bottom and Ag nanorods at the top, similar to those observed in the Ag−Co−TiO 2 film on the LaSrAlO 4 insulate substrate. 25 The Ag−Co nanomatch-like structures are located in the film matrix ∼5 nm apart from the seed layer. Each Ag nanorod with a dimension of ∼5 nm in diameter and ∼10 nm in length grows from a Co nanosphere toward the film surface.…”

Strain, magnetic anisotropy, and composition modulation in hybrid metal–oxide vertically assembled nanocomposites

“…However, the equilibrium VAN configurations resulting from co-deposition of these metals are also strongly influenced by differences in their surface energy. Co-growth of Au-Co-STO and Ag-Co-TiO 2 produced bilayered NWs, with the component with lower surface energy located at the NW top: 23,43,44 Au and Ag act as metallic surfactants, pushing incoming Co atoms to the bottom of the NW (Figure 4b), which additionally minimizes the interface between the two immiscible metallic phases. Similar processes have also been observed in threephase metal/oxide/oxide composites.…”