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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Gold nanowire growth through stacking fault mechanism by oleylamine-mediated synthesis

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Moraes, Daniel A. [1] ; Souza Junior, Joao B. [1] ; Ferreira, Fabio F. [2] ; Mogili, Naga Vishnu V. [3] ; Varanda, Laudemir C. [1]
Total Authors: 5
[1] Univ Sao Paulo, Inst Quim Sao Carlos, Phys Chem Dept, Colloidal Mat Grp, BR-13566590 Sao Carlos, SP - Brazil
[2] Univ Fed ABC, Ctr Ciencias Nat & Humans, BR-09210580 Santo Andre, SP - Brazil
[3] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Nanotechnol Natl Lab LNNano, BR-13083970 Campinas, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: NANOSCALE; v. 12, n. 25, p. 13316-13329, JUL 7 2020.
Web of Science Citations: 4

Tadpole-like gold nanowires were obtained by the oleylamine-mediated synthesis presenting an unusual mixture of fcc and hcp phases. Structural analyses were performed to understand their structure and growth using aberration-corrected high-resolution scanning transmission electron microscopy and electron diffraction at the tail region of tadpoles showing that the anisotropic shape occurred due to stacking fault defects. Stacking faults and twin defects are responsible for the hcp phase inferring a defect dependent growth. The stacking fault model used in X-ray diffraction (XRD) refinement resulted in 60% of hcp stacking sequences. Temperature-dependent XRD analyses showed that the faults become unstable around 120 degrees C, and it is completely converted to the fcc phase at 230 degrees C. We attribute the nanowire formation to a stacking fault mechanism of growth that begins in the later stage of nanoparticle growth. The UV-Vis spectrum presented two localized surface plasmon resonance bands at 500 nm and from 800 nm extending to near-infrared, associated with transverse and longitudinal modes, respectively. A surprising ferromagnetic behavior is also observed with a blocking temperature near 300 K. (AU)

FAPESP's process: 12/02093-3 - Synthesis of Co@Au (superparamagnetics) and CdSe@Zn (quantum dots) core@shell nanostructures for applications as antineoplasia agents
Grantee:João Batista Souza Junior
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 13/01284-2 - Theranostic nanoparticles based in superparamagnetic iron oxide for skin cancer therapy by magnetic hyperthermia
Grantee:Laudemir Carlos Varanda
Support type: Regular Research Grants