Selective exposition of high and low density crystal facets of gold nanocrystals using the seeded-growth technique

CrystEngComm ◽  
2011 ◽  
Vol 13 (3) ◽  
pp. 850-856 ◽  
Author(s):  
Heidrun A. Keul ◽  
Martin Möller ◽  
Michael R. Bockstaller
Keyword(s):  
Low Density ◽  
Seeded Growth ◽  
Growth Technique ◽  
Gold Nanocrystals

Enriching the branching of Au@PdAu core–shell nanocrystals using a syringe pump: kinetics control meets lattice mismatch

CrystEngComm ◽  
2021 ◽  
Vol 23 (13) ◽  
pp. 2582-2589
Author(s):  
Gongguo Zhang ◽  
Yanyun Ma ◽  
Xiaowei Fu ◽  
Wenjun Zhao ◽  
Feng Liu ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Surface Diffusion ◽  
Lattice Mismatch ◽  
Core Shell ◽  
Syringe Pump ◽  
Seeded Growth ◽  
Gold Nanocrystals

Gold@palladium–gold nanocrystals with a tunable branched shape are prepared via seeded growth, where the use of a syringe pump allows the manipulation over reaction kinetics as coupled by surface diffusion and strain caused by lattice mismatch.

One-step seeded growth of monodisperse, quasi-spherical, Tris-stabilized gold nanocrystals with sizes from 17 to 325 nm

CrystEngComm ◽  
2017 ◽  
Vol 19 (2) ◽  
pp. 318-324 ◽  
Author(s):  
Yijing Li ◽  
Peina Zhang ◽  
Junling Duan ◽  
Shiyun Ai ◽  
Houshen Li
Keyword(s):  
Seeded Growth ◽  
Gold Nanocrystals ◽  
One Step

Numerical Studies of Semiconductor Materials Solidification With Applied Electric and Magnetic Fields

2001 ◽  
Author(s):  
Peng Zhang ◽  
Lili Zheng ◽  
Gerald Iseler ◽  
David Bliss
Keyword(s):  
Crystal Growth ◽  
Magnetic Fields ◽  
Semiconductor Materials ◽  
Concerted Effort ◽  
Seeded Growth ◽  
Gravitational Convection ◽  
Growth Technique ◽  
Thermal Distribution ◽  
Numerical Studies ◽  
Electric And Magnetic Fields

Abstract This paper presents one part of a concerted effort to understand the solidification and crystal growth of semiconductor materials using the bottom-seeded growth technique with externally applied electric and magnetic fields. A physics-based model is developed to study the gravitational (convection), thermoelectric (Peltier, Seebeck, Joule and Thomson) and magnetohydrodynamic (Lorentz force) effects on solidification phenomena. Several combinations of the magnitudes and directions of the two fields are studied. The calculated effects of the applied electrical and magnetic fields on the thermal distribution and position and shape of the solidification front are presented for bottom-seeded GaSb growth.

Study on Controlled Size, Shape and Dispersity of Gold Nanoparticles (AuNPs) Synthesized via Seeded-Growth Technique for Immunoassay Labeling

2011 ◽  
Vol 364 ◽  
pp. 504-509 ◽  
Author(s):  
Rabizah Makhsin Siti ◽  
Abdul Razak Khairunisak ◽  
Azlan Abdul Aziz ◽  
Rahmah Noordin
Keyword(s):  
Gold Nanoparticles ◽  
Size Range ◽  
Trisodium Citrate ◽  
Test Strip ◽  
Seeded Growth ◽  
Growth Technique ◽  
Seed Solution ◽  
Transmission Electron ◽  
Spherical Gold Nanoparticles ◽  
Solution Volume

This study describes the formation of spherical gold nanoparticles (AuNPs) using a simple seeded-growth technique. The size and surface morphology of AuNPs were investigated using transmission electron microscopy (TEM) and UV-Vis spectrophotometer was used to determine the wavelength and absorption of AuNPs. In the seed stage, the effect of trisodium citrate volume was studied. The size of AuNPs at seed stage was varied from 15 to 40 nm with decreasing volume of trisodium citrate. In the growth stage, the effects of seed solution volume and concentration of hydroxylamine were studied. The size of AuNPs produced became larger when the amount of seed solution was reduced. This approach was beneficial to produce AuNPs with the size range from 15 to 150 nm. The increase of hydroxylamine concentration increased the size of AuNPs. However, after the concentration of hydroxylamine reached supersaturation condition (3 M NH2OH.HCl), the AuNPs formed in a bulk and clusters. Selected sizes of AuNPs were then conjugated to antibody and proved by testing on the immunoassay test strip. The observation using naked eyes for the appearance of red lines on the immunoassay test strip showed that AuNPs were successfully conjugated to antibody and specifically bound to the antigen drawn on the strip assay by tested with positive and negative serum of the disease.

Preparation of monodisperse silica particles with controllable size and shape

2003 ◽  
Vol 18 (3) ◽  
pp. 649-653 ◽  
Author(s):  
J. H. Zhang ◽  
P. Zhan ◽  
Z. L. Wang ◽  
W. Y. Zhang ◽  
N. B. Ming
Keyword(s):  
Photonic Band Gap ◽  
Silica Particles ◽  
Tetraethyl Orthosilicate ◽  
Gap Effect ◽  
Silica Spheres ◽  
Seeded Growth ◽  
Growth Technique ◽  
Monodisperse Silica ◽  
Photonic Band ◽  
Controllable Size

The effects of dilution of tetraethyl orthosilicate (TEOS) with ethanol on the shape and monodispersity of silica particles were investigated. The results indicated that the dilution of TEOS with ethanol can depress the formation of new nuclei and the aggregation or adhesion of particles and make the distillation of TEOS unnecessary to achieve monodispersed silica spheres. A seeded growth technique using continuous drop addition of TEOS diluted with 4× volume of ethanol was developed to improve monodispersity and spheric shape and increase the size of silica particles. The monodisperse silica particles (150 nm ± 5%−1.2 μm ± 1%) with fine spheric shape were successfully synthesized by the seeded growth technique. Using the homemade 280 nm ± 2.8% silica spheres, we prepared opals of high quality which showed periodically ordered packing and a photonic band-gap effect.

Crystallinity Variation in Seeded Growth of Gold Nanocrystals: the Role of Additive Ag +

2020 ◽  
Vol 5 (15) ◽  
pp. 4447-4453 ◽  
Author(s):  
Gongguo Zhang ◽  
Xiaowei Fu ◽  
Zhiang Liu ◽  
Xiaoqian Luan ◽  
Fengli Qu ◽  
...  
Keyword(s):  
Seeded Growth ◽  
Gold Nanocrystals

scholarly journals Micelle-directed chiral seeded growth on anisotropic gold nanocrystals

Science ◽  
2020 ◽  
Vol 368 (6498) ◽  
pp. 1472-1477 ◽  
Author(s):  
Guillermo González-Rubio ◽  
Jesús Mosquera ◽  
Vished Kumar ◽  
Adrián Pedrazo-Tardajos ◽  
Pablo Llombart ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Near Infrared ◽  
Mixed Micelles ◽  
Electromagnetic Spectrum ◽  
Seeded Growth ◽  
Gold Nanocrystals ◽  
Direct Seeded ◽  
Templating Effect ◽  
Surfactant Assisted ◽  
Plasmon Modes

Surfactant-assisted seeded growth of metal nanoparticles (NPs) can be engineered to produce anisotropic gold nanocrystals with high chiroptical activity through the templating effect of chiral micelles formed in the presence of dissymmetric cosurfactants. Mixed micelles adsorb on gold nanorods, forming quasihelical patterns that direct seeded growth into NPs with pronounced morphological and optical handedness. Sharp chiral wrinkles lead to chiral plasmon modes with high dissymmetry factors (~0.20). Through variation of the dimensions of chiral wrinkles, the chiroptical properties can be tuned within the visible and near-infrared electromagnetic spectrum. The micelle-directed mechanism allows extension to other systems, such as the seeded growth of chiral platinum shells on gold nanorods. This approach provides a reproducible, simple, and scalable method toward the fabrication of NPs with high chiral optical activity.

Application of Improved Voltage Compensation in the SEM to Imaging of Organic Materials

1973 ◽  
Vol 31 ◽  
pp. 444-445
Author(s):  
P.J. Killingworth ◽  
M. Warren
Keyword(s):  
Electron Beam ◽  
Organic Materials ◽  
Operating Parameters ◽  
Low Density ◽  
Beam Diameter ◽  
Incident Electron Beam ◽  
Specimen Material ◽  
Voltage Compensation ◽  
Selection Of ◽  
Scanning Electron

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.

Quantitative defect studies in semiconductor TEM samples prepared by low angle ion milling

1995 ◽  
Vol 53 ◽  
pp. 512-513
Author(s):  
L. Mulestagno ◽  
J.C. Holzer ◽  
P. Fraundorf
Keyword(s):  
Sample Preparation ◽  
Milling Time ◽  
High Density ◽  
Low Density ◽  
Ion Milling ◽  
High Quality ◽  
Variable Angle ◽  
Major Disadvantage ◽  
Induced Defects

Due to the wealth of information, both analytical and structural that can be obtained from it TEM always has been a favorite tool for the analysis of process-induced defects in semiconductor wafers. The only major disadvantage has always been, that the volume under study in the TEM is relatively small, making it difficult to locate low density defects, and sample preparation is a somewhat lengthy procedure. This problem has been somewhat alleviated by the availability of efficient low angle milling.Using a PIPS® variable angle ion -mill, manufactured by Gatan, we have been consistently obtaining planar specimens with a high quality thin area in excess of 5 × 104 μm2 in about half an hour (milling time), which has made it possible to locate defects at lower densities, or, for defects of relatively high density, obtain information which is statistically more significant (table 1).

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