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Title: Templated Control of Au nanospheres in Silica Nanowires

Abstract

The formation of regularly-spaced metal nanostructures in selectively-placed insulating nanowires is an important step toward realization of a wide range of nano-scale electronic and opto-electronic devices. Here we report templated synthesis of Au nanospheres embedded in silica nanowires, with nanospheres consistently spaced with a period equal to three times their diameter. Under appropriate conditions, nanowires form exclusively on Si nanostructures because of enhanced local oxidation and reduced melting temperatures relative to templates with larger dimensions. We explain the spacing of the nanospheres with a general model based on a vapor-liquid-solid mechanism, in which an Au/Si alloy dendrite remains liquid in the nanotube until a critical Si concentration is achieved locally by silicon oxide-generated nanowire growth. Additional Si oxidation then locally reduces the surface energy of the Au-rich alloy by creating a new surface with minimum area inside of the nanotube. The isolated liquid domain subsequently evolves to become an Au nanosphere, and the process is repeated.

Authors:
; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
943834
Report Number(s):
UCRL-JRNL-229297
Journal ID: ISSN 0021-8979; JAPIAU; TRN: US200902%%440
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics, vol. 104, no. 9, November 12, 2008, pp. 094317; Journal Volume: 104; Journal Issue: 9
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 42 ENGINEERING; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 71 CLASSICAL AND QUANTUMM MECHANICS, GENERAL PHYSICS; ALLOYS; DENDRITES; DIMENSIONS; MELTING; NANOSTRUCTURES; NANOTUBES; OXIDATION; SILICA; SILICON; SURFACE ENERGY; SYNTHESIS

Citation Formats

Tringe, J W, Vanamu, G, and Zaidi, S H. Templated Control of Au nanospheres in Silica Nanowires. United States: N. p., 2007. Web.
Tringe, J W, Vanamu, G, & Zaidi, S H. Templated Control of Au nanospheres in Silica Nanowires. United States.
Tringe, J W, Vanamu, G, and Zaidi, S H. Thu . "Templated Control of Au nanospheres in Silica Nanowires". United States. doi:. https://www.osti.gov/servlets/purl/943834.
@article{osti_943834,
title = {Templated Control of Au nanospheres in Silica Nanowires},
author = {Tringe, J W and Vanamu, G and Zaidi, S H},
abstractNote = {The formation of regularly-spaced metal nanostructures in selectively-placed insulating nanowires is an important step toward realization of a wide range of nano-scale electronic and opto-electronic devices. Here we report templated synthesis of Au nanospheres embedded in silica nanowires, with nanospheres consistently spaced with a period equal to three times their diameter. Under appropriate conditions, nanowires form exclusively on Si nanostructures because of enhanced local oxidation and reduced melting temperatures relative to templates with larger dimensions. We explain the spacing of the nanospheres with a general model based on a vapor-liquid-solid mechanism, in which an Au/Si alloy dendrite remains liquid in the nanotube until a critical Si concentration is achieved locally by silicon oxide-generated nanowire growth. Additional Si oxidation then locally reduces the surface energy of the Au-rich alloy by creating a new surface with minimum area inside of the nanotube. The isolated liquid domain subsequently evolves to become an Au nanosphere, and the process is repeated.},
doi = {},
journal = {Journal of Applied Physics, vol. 104, no. 9, November 12, 2008, pp. 094317},
number = 9,
volume = 104,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
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  • Understanding domain wall pinning and propagation in nanowires are important for future spintronics and nanoparticle manipulation technologies. Here, the effects of microscopic local modification of the magnetic properties, induced by focused-ion-beam intermixing, in NiFe/Au bilayer nanowires on the pinning behavior of domain walls was investigated. The effects of irradiation dose and the length of the irradiated features were investigated experimentally. The results are considered in the context of detailed quasi-static micromagnetic simulations, where the ion-induced modification was represented as a local reduction of the saturation magnetization. Simulations show that domain wall pinning behavior depends on the magnitude of the magnetizationmore » change, the length of the modified region, and the domain wall structure. Comparative analysis indicates that reduced saturation magnetisation is not solely responsible for the experimentally observed pinning behavior.« less