Core-shell Ge Nanoparticles on Oxide Surfaces for Enhanced Interface Stability

2006 ◽  
Vol 933 ◽  
Author(s):  
Scott K. Stanley ◽  
John G. Ekerdt
Keyword(s):  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Core Shell ◽  
Ion Scattering ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Low Energy Ion Scattering ◽  
Core Shell Nanoparticles ◽  
Thermal Stability Of

ABSTRACTGermanium nanoparticles are grown on HfO2 substrates by hot-wire chemical vapor deposition (HWCVD). The oxidation and thermal stability of these unmodified Ge nanoparticles are determined with X-ray photoelectron spectroscopy (XPS). Core-shell nanoparticles were then prepared by growing the Ge cores with HWCVD and selectively growing Si or C shell layers on the Ge cores by conventional CVD. The formation of core-shell nanoparticles was monitored with XPS and low energy ion scattering. Large differences are observed in the thermal stability and oxide formation for unmodified Ge and the different core-shell nanoparticles.

Thermal Stability of Core–Shell Nanoparticles: A Combined in Situ Study by XPS and TEM

2015 ◽  
Vol 27 (20) ◽  
pp. 6960-6968 ◽  
Author(s):  
Cecile S. Bonifacio ◽  
Sophie Carenco ◽  
Cheng Hao Wu ◽  
Stephen D. House ◽  
Hendrik Bluhm ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
In Situ Study ◽  
Core Shell Nanoparticles ◽  
Thermal Stability Of

Synchrotron Radiation X-ray Photoelectron Spectroscopy as a Tool To Resolve the Dimensions of Spherical Core/Shell Nanoparticles

2014 ◽  
Vol 118 (46) ◽  
pp. 26621-26628 ◽  
Author(s):  
Won Hui Doh ◽  
Vasiliki Papaefthimiou ◽  
Thierry Dintzer ◽  
Véronique Dupuis ◽  
Spyridon Zafeiratos
Keyword(s):  
Synchrotron Radiation ◽  
Photoelectron Spectroscopy ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Spherical Core ◽  
Core Shell Nanoparticles

Synthesis of Fe3O4/ZnO Core-shell Nanoparticles for Photodynamic Therapy Applications

2010 ◽  
Vol 1257 ◽  
Author(s):  
Juan C. Beltran Huarac ◽  
Surinder P. Singh ◽  
Maharaj S. Tomar ◽  
Sandra Peňa ◽  
Luis Rivera ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Singlet Oxygen ◽  
Photoelectron Spectroscopy ◽  
Green Emission ◽  
Core Shell ◽  
Light Sources ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Core Shell Nanoparticles

AbstractThe use of nanoparticles as carriers of photosensitizer (PS) molecules for photodynamic therapy (PDT) has attracted much interest on core-shell nanosize structures. Herein, we used a simple aqueous solution method to synthesize Fe3O4/ZnO core-shell nanoparticles. X-ray diffraction (XRD) analyses showed the presence of well defined peaks corresponding to Fe3O4 and ZnO in as-synthesized nanocrystals. Vibrating sample magnetometer (VSM) measurements showed that these nanoparticles exhibited superparamagnetic behavior of the core with no coercivity nor remanence. X-ray photoelectron spectroscopy (XPS) analyses revealed the presence of Zn1/2 and Zn3/2 species on the surface of nanocrystals. Photoluminescence measurements showed excitonic emission of ZnO co-existing with a weak and broad defect- related green emission at room temperature. The generation of singlet oxygen was monitored via the photooxidation of diphenyl-1,3-isobenzofuran (DPBF) with different light sources, followed by absorption spectroscopy at 409 nm. The capability of synthesized nanoparticles to generate singlet oxygen has also been verified.

Computer Modeling of the Formation Process of Core-Shell Nanoparticles Cu@Si

2018 ◽  
Vol 271 ◽  
pp. 47-50 ◽  
Author(s):  
Natalia V. Yumozhapova ◽  
Andrey V. Nomoev ◽  
Yuri Ya. Gafner
Keyword(s):  
Thermal Stability ◽  
Formation Process ◽  
Molecular Dynamic Method ◽  
Dynamic Method ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Droplet Behavior ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles ◽  
Thermal Stability Of

The process of nanoparticle Cu@Si formation by the molecular dynamic method using MEAM-potentials was studied. Modeling the droplet behavior demonstrates that a core-shell structure with a copper core and a silicon shell can be formed if the drop is in the liquid state, until the material is finally redistributed. The parameters of thermal stability of Cu@Si composite nanoparticles of different sizes have been determined. It is concluded that as the temperature increases, the diffusion of copper atoms to the surface begins, which leads to a change in the structure and the formation of particles with a core of the Cu@Si type.

Synthesis, characterization, and femtosecond third-order optical nonlinearity of Au@Ag core–shell nanoparticles

2021 ◽  
Author(s):  
Heng Lu ◽  
Bing Gu
Keyword(s):  
Absorption Spectrum ◽  
Photoelectron Spectroscopy ◽  
Nonlinear Refraction ◽  
Optical Nonlinearity ◽  
Core Shell ◽  
Third Order ◽  
Shell Nanoparticles ◽  
Linear Absorption ◽  
X Ray ◽  
Core Shell Nanoparticles

In this work, the Au@Ag bimetallic core–shell nanostructures were synthesized by a seed-mediated growth. The crystal structure, morphology, elemental composition, atomic concentration, and absorption spectrum of the as-synthesized nanoparticles were characterized by means of X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible linear absorption spectrum, respectively. The femtosecond third-order optical nonlinearities of nanoparticle dispersions were investigated by carrying out the femtosecond-pulsed [Formula: see text]-scan measurements at 800[Formula: see text]nm. The experimental results indicate that Au@Ag core–shell nanoparticles exhibit the positive refractive nonlinearity and negative absorptive nonlinearity. The third-order nonlinear refraction indexes of Au and Au@Ag nanoparticles are measured to be [Formula: see text] and [Formula: see text][Formula: see text]cm2/GW, respectively. The results show that the bimetallic nanoparticle has potential possibility in nonlinear photonic applications.

Fe3O4@ZrO2 magnetic nanoparticles as a new electrode material for sensitive determination of organophosphorus agents

2015 ◽  
Vol 7 (12) ◽  
pp. 5053-5059 ◽  
Author(s):  
Na-Na Li ◽  
Tian-Fang Kang ◽  
Jing-Jing Zhang ◽  
Li-Ping Lu ◽  
Shui-Yuan Cheng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Magnetic Core ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Sensitive Determination ◽  
Core Shell Nanoparticles

In this study, Fe3O4@ZrO2 magnetic core–shell nanoparticles (NPs) were synthesized and were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).

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