General Equation for Size Nanocharacterization of the Core−Shell Nanoparticles by X-ray Photoelectron Spectroscopy

2005 ◽  
Vol 109 (18) ◽  
pp. 8733-8737 ◽  
Author(s):  
Jean-Numa Gillet ◽  
Michel Meunier
Keyword(s):  
Photoelectron Spectroscopy ◽  
General Equation ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
X Ray ◽  
The Core ◽  
Core Shell Nanoparticles

scholarly journals Synthesis, Characterization, and Optimization of Magnetoelectric BaTiO3–Iron Oxide Core–Shell Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 563 ◽  
Author(s):  
Mahmud Reaz ◽  
Ariful Haque ◽  
Kartik Ghosh
Keyword(s):  
Iron Oxide ◽  
Photoelectron Spectroscopy ◽  
Oxide Phase ◽  
Rietveld Analysis ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
X Ray ◽  
The Core ◽  
Iron Oxide Core ◽  
Core Shell Nanoparticles

Improvement of magnetic, electronic, optical, and catalytic properties in cutting-edge technologies including drug delivery, energy storage, magnetic transistor, and spintronics requires novel nanomaterials. This article discusses the unique, clean, and homogeneous physiochemical synthesis of BaTiO3/iron oxide core–shell nanoparticles with interfaces between ferroelectric and ferromagnetic materials. High-resolution transmission electron microscopy displayed the distinguished disparity between the core and shell of the synthesized nanoparticles. Elemental mapping and line scan confirmed the formation of the core–shell structure. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy detected the surface iron oxide phase as maghemite. Rietveld analysis of the X-ray diffraction data labeled the crystallinity and phase purity. This study provides a promising platform for the desirable property development of the futuristic multifunctional nanodevices.

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

scholarly journals Luminescence Nanothermometry Based on Pr3+ : LaF3 Single Core and Pr3+ : LaF3/LaF3 Core/Shell Nanoparticles

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
M. S. Pudovkin ◽  
D. A. Koryakovtseva ◽  
E. V. Lukinova ◽  
S. L. Korableva ◽  
R. Sh. Khusnutdinova ◽  
...  
Keyword(s):  
Coherent Scattering ◽  
Core Shell ◽  
Fluorescence Intensity Ratio ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
The Core ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Core Shell Nanoparticles

Core Pr3+ : LaF3 (CPr = 1%) plate-like nanoparticles (nanoplates), core/shell Pr3+ : LaF3 (CPr = 1%)/LaF3 nanoplates, core Pr3+ : LaF3 (CPr = 1%) sphere-like nanoparticles (nanospheres), and core/shell Pr3+ : LaF3 (CPr = 1%)/LaF3 nanospheres were synthesized via the coprecipitation method of synthesis. The nanoparticles (NPs) were characterized by means of transmission electron microscopy, X-ray diffraction, and optical spectroscopy. The formation of the shell was proved by detecting the increase in physical sizes, sizes of coherent scattering regions, and luminescence lifetimes of core/shell NPs comparing with single core NPs. The average physical sizes of core nanoplates, core/shell nanoplates, core nanospheres, and core/shell nanospheres were 62.2 ± 0.9, 74.7 ± 1.2, 13.8 ± 0.9 and 22.0 ± 1.2 nm, respectively. The formation of the NP shell led to increasing of effective luminescence lifetime τeff of the 3P0 state of Pr3+ ions for the core nanoplates, core/shell nanoplates, core nanospheres, and core/shell nanospheres the values of τeff were 2.3, 3.6, 3.2, and 4.7 μsec, respectively (at 300 K). The values of absolute sensitivity Sa for fluorescence intensity ratio (FIR) thermometry was 0.01 K−1 at 300 K for all the samples. The FIR sensitivity can be attributed to the fact that 3P1 and 3P0 states share their electronic populations according to the Boltzmann process. The values of Sa for lifetime thermometry for core nanoplates, core/shell nanoplates, core nanospheres, and core/shell nanospheres were (36.4 ± 3.1) · 10−4, (70.7 ± 5.9) · 10−4, (40.7 ± 2.6) · 10−4, and (68.8 ± 2.4) · 10−4 K−1, respectively.

Magnetic Behaviour of FeCo/Cu Core Shell Nanoparticles

2016 ◽  
Vol 719 ◽  
pp. 3-8
Author(s):  
Angshuman Sarkar ◽  
Shilabati Hembram ◽  
Subhranshu Chatterjee ◽  
Pritam Deb ◽  
Amitava Basu Mallick
Keyword(s):  
Magnetic Properties ◽  
Annealing Temperature ◽  
Field Enhancement ◽  
Blocking Temperature ◽  
Core Shell ◽  
Line Profile Analysis ◽  
Shell Nanoparticles ◽  
X Ray ◽  
The Core ◽  
Core Shell Nanoparticles

In the present investigation, FeCo/Cu core shell nanoparticles were prepared by coating a Cu layer over FeCo alloy nanoparticles through displacement reaction. X-ray diffraction studies confirmed the presence of FeCo and Cu phases in the sample. The grain size and lattice strains of the core shell nanostructures were evaluated from the x-ray profiles by using single line profile analysis technique. The effect of annealing temperature on the magnetic properties of the core shell nanoparticles was studied by using a vibrating sample magnetometer. The results showed that the magnetic properties improve significantly after annealing the compacts of core shell nanoparticles under a magnetic field. Enhancement in magnetization was observed in the compacts with the increase in annealing temperature. Highest saturation magnetization value of 56 emu/g was recorded in the sample which was annealed at 600°C. It has been also found that the blocking temperature of the core shell nanoparticles increases with the increase in annealing temperature.

Synthesis and Characterization of Co3O4-MnxCo3-xO4 Core-Shell Nanoparticles

MRS Advances ◽  
2018 ◽  
Vol 3 (47-48) ◽  
pp. 2899-2904
Author(s):  
Ning Bian ◽  
Robert A. Mayanovic ◽  
Mourad Benamara
Keyword(s):  
Electron Microscopy ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Blocking Temperature ◽  
Core Shell ◽  
Average Particle ◽  
Shell Nanoparticles ◽  
X Ray ◽  
The Core ◽  
Core Shell Nanoparticles

ABSTRACTThe mixed-valence oxide Co3O4 nanoparticles, having the normal spinel structure, possess large surface area, active-site surface adsorption properties, and fast ion diffusivities. Consequently, they are widely used in lithium-ion batteries, as well as for gas sensing and heterogeneous catalysis applications. In our research, we use a two-step method to synthesize Co3O4–based core-shell nanoparticles (CSNs). Cobalt oxide (Co3O4) nanoparticles were successfully synthesized using a wet synthesis method employing KOH and cobalt acetate. Manganese was incorporated into the Co3O4 structure to synthesize inverted Co3O4@MnxCo3-xO4 CSNs using a hydrothermal method. By adjustment of pH value, we obtained two different morphologies of CSNs, one resulting in pseudo-spherical and octahedron-shaped nanoparticles (PS type) whereas the second type predominantly have a nanoplate (NP type) morphology. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS) have been performed in order to determine the morphological and structural properties of our CSNs, whereas the magnetic properties have been characterized using a superconducting quantum interference device (SQUID) magnetometer. XRD and TEM results show that the CSNs have the same spinel crystal structure throughout the core and shell with an average particle size of ∼19.8 nm. Our Co3O4 nanoparticles, as measured prior to CSN formation, are shown to be antiferromagnetic (AFM) in nature as shown by the magnetization data. Our SQUID data indicate that the core-shell nanoparticles have both AFM (due to the Co3O4 core) and ferrimagnetic properties (of the shell) with a coercivity field of 300 Oe and 150 Oe at 5 K for the PS and NP samples, respectively. The magnetization vs temperature data show a spin order-disorder transition at ∼33 K and a superparamagnetic blocking temperature of ∼90 K for both batches.

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.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document