Structural Characterization of Ultrathin Epitaxial ErSi2−x on Si(111)

1990 ◽  
Vol 198 ◽  
Author(s):  
F.H. Kaatz ◽  
J. Van der Spiegel ◽  
W.R. Graham
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Domain Formation ◽  
Plan View ◽  
Superlattice Structure ◽  
Transmission Electron ◽  
Vacancy Ordering ◽  
Ultrathin Layers ◽  
Temperature Deposition

ABSTRACTThe epitaxial structure of ErSi2−x on Si(1 11) has been investigated using Rutherford backscattering (RBS) and transmission electron microscopy (TEM). Films 10 nm. thick show channeling minimum yields of 4% after room temperature deposition and annealing to 800°C. Plan view electron microscopy on ultrathin layers 0.5 nm. to 10 nm. thick reveals the formation of a complex microstructure involving vacancy ordering in these films. This superlattice structure is interpreted by considering domain formation and twinning in the heteroepitaxial ErSi2−x.

Characterization of Ultrathin Cosi2 on Si(111) Layers.

1987 ◽  
Vol 91 ◽  
Author(s):  
J.L. Batstone ◽  
Julia M. Phillips ◽  
J.M. Gibson
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Room Temperature ◽  
Misfit Dislocations ◽  
Transmission Electron ◽  
High Temperature Anneal ◽  
Temperature Deposition ◽  
Regular Network ◽  
Pseudomorphic Growth

ABSTRACTUltrathin epitaxial CoSi2 films on Si(111) have been grown in ultrahigh vacuum by room temperature deposition of Co on Si(111) followed by a high temperature anneal at ~600°C. Characterization of the thin films with transmission electron microscopy has revealed pseudomorphic growth up to thicknesses ~30Å. Pinholes present in the pseudomorphic thin films are thought to prevent the trapping of dislocations within the film. A clear transition to films containing a regular network of misfit dislocations occurs at ~40Å. Evidence for the growth of CoSi2 via intermediate metal-rich silicide phases is observed.

L-cysteine functionalized graphene quantum dots for sub-ppb detection of As (III)

2021 ◽  
Author(s):  
Md. Farhan Naseh ◽  
Neelam Singh ◽  
Jamilur R. Ansari ◽  
Ashavani Kumar ◽  
Tapan Sarkar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Room Temperature ◽  
Graphene Quantum Dots ◽  
Optical Characterization ◽  
Functionalized Graphene ◽  
Transmission Electron ◽  
Sensitivity And Selectivity ◽  
Structural Characterizations

Abstract Here, we report functionalized graphene quantum dots (GQDs) for the optical detection of arsenic at room temperature. GQDs with the fluorescence of three fundamental colors (red, green, and blue) were synthesized and functionally capped with L-cysteine (L-cys) to impart selectively towards As (III) by exploiting the affinity of L-cys towards arsenite. The optical characterization of GQDs was carried out using UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy, and fluorescence spectrometry and the structural characterizations were performed using transmission electron microscopy. The fluorescence results showed instantaneous quenching in intensity when the GQDs came in contact with As (III) for all test concentrations over a range from 0.025 ppb to 25 ppb, which covers the permissible limit of arsenic in drinking water. The experimental results suggested excellent sensitivity and selectivity towards As (III).

Cross-Sectional TEM Studies of Indentation-Induced Phase Transformations in Si: Indenter Angle Effects

2004 ◽  
Vol 843 ◽  
Author(s):  
Songqing Wen ◽  
James Bentley ◽  
Jae-il Jang ◽  
G. M. Pharr
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Indentation Load ◽  
High Load ◽  
Cross Sectional ◽  
Plan View ◽  
Transmission Electron ◽  
Cube Corner ◽  
Displacement Behavior ◽  
Si Wafer

ABSTRACTNanoindentations were made on a (100) single crystal Si wafer at room temperature with a series of triangular pyramidal indenters having centerline-to-face angles ranging from 35° to 85°. Indentations produced at high (80 mN) and low (10 mN) loads were examined in plan-view by scanning electron microscopy and in cross-section by transmission electron microscopy. Microstructural observations were correlated with the indentation load-displacement behavior. Cracking and extrusion are more prevalent for sharp indenters with small centerline-to-face angles, regardless of the load. At low loads, the transformed material is amorphous silicon for all indenter angles. For Berkovich indentations made at high-load, the transformed material is a nanocrystalline mix of Si-I and Si-III/Si-XII, as confirmed by selected area diffraction. Extrusion of material at high loads for the cube-corner indenter reduces the volume of transformed material remaining underneath the indenter, thereby eliminating the pop-out in the unloading curve.

Imaging of Buried Si and Si:Ge Surface Structure Under Amorphous Ge Films by Plan View Transmission Electron Microscopy

1994 ◽  
Vol 332 ◽  
Author(s):  
Olof C. Hellman
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Shift ◽  
Room Temperature ◽  
Real Space ◽  
Interfacial Structure ◽  
Tem Analysis ◽  
Plan View ◽  
Transmission Electron ◽  
Reconstructed Surface

ABSTRACTReal space plan-view Transmission Electron Microscopy (TEM) of the interfacial structure at the amorphous-Ge / Si (111) interface is presented. Ge is deposited at between room temperature and 150°C on either a 5×5 or 7×7 reconstructed surface. Conventional Plan-view TEM analysis reveals microstructural details such as surface steps, reconstruction phase shift boundaries and the reconstruction itself buried under the amorphous film, features which have previously been seen only as clean surfaces in UHV. Also imaged are small regions where Ge grows epitaxially on the Si surface above room temperature. These are seen to appear preferentially at steps and phase shift boundaries.

Solvothermal Synthesis and Characterization of Lithium Tantalate Nanoparticles

2014 ◽  
Vol 602-603 ◽  
pp. 19-22 ◽  
Author(s):  
Lin Qiang Gao ◽  
Hai Yan Chen ◽  
Zhen Wang ◽  
Xin Zou
Keyword(s):  
Electron Microscopy ◽  
Solvothermal Synthesis ◽  
Room Temperature ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Particle Size And Morphology ◽  
Size And Morphology

Nanoscale LiTaO3 powders with perovskite structure were synthesized using the solvothermal technique with glycol as solvent at 240°C for 12h. The powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). XRD was used to elucidate room temperature structures using Rietveld refinement. The powders were pure single pervoskite phase with high crystallinity. FESEM and TEM were used to determine particle size and morphology. The average LiTaO3 grain size was estimated to be < 200nm, and TEM images indicated that LiTaO3 particles had a brick-like morphology. In addition, the effect of the temperature on the LiTaO3 power characterisitics was also detailed studied.

Synthesis and Characterization of Sliver Nanoparticles in KH-550 DMF Solution

2012 ◽  
Vol 557-559 ◽  
pp. 624-627
Author(s):  
Yan Ming Chen ◽  
Jiao Han
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Room Temperature ◽  
Synthesis And Characterization ◽  
Characteristic Surface ◽  
Surface Plasmon Band ◽  
Plasmon Band ◽  
Transmission Electron ◽  
Sliver Nanoparticles

Silver nanoparticles have been synthesized in 3-(aminopropyl)triethoxysilane (KH-550) solution using DMF (N, N-dimethylformamide) as both solvent and reductant at room temperature and 120°C. A characteristic surface plasmon band can be observed for the obtained silver nanoparticles from UV-vis absorption spectra, which indicate that KH-550 can serve as stabilizing agent for the formation of silver nanoparticles. Transmission electron microscopy (TEM) results show that silver nanoparticles with different sizes were obtained by simply controlling the reaction temperature.

Nanocrystalline and stacking-disordered β-cristobalite AlPO4 chemically stabilized at room temperature: synthesis, physical characterization, and X-ray powder diffraction data

2017 ◽  
Vol 32 (S1) ◽  
pp. S193-S200
Author(s):  
B. Peplinski ◽  
B. Adamczyk ◽  
P. Formanek ◽  
C. Meyer ◽  
O. Krüger ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Powder Diffraction ◽  
Title Compound ◽  
Room Temperature ◽  
Optical Emission ◽  
Xrd Pattern ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron

This paper reports the first successful synthesis and the structural characterization of nanocrystalline and stacking-disordered β-cristobalite AlPO4 that is chemically stabilized down to room temperature and free of crystalline impurity phases. Several batches of the title compound were synthesized and thoroughly characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy mapping in SEM, solid-state 31P nuclear magnetic resonance (31P-NMR) spectroscopy including the TRAPDOR method, differential thermal analysis (DTA), gas-sorption methods, optical emission spectroscopy, X-ray fluorescence spectroscopy, and ion chromatography. Parameters that are critical for the synthesis were identified and optimized. The synthesis procedure yields reproducible results and is well documented. A high-quality XRD pattern of the title compound is presented, which was collected with monochromatic copper radiation at room temperature in a wide 2θ range of 5°–100°.

RBS, TEM and SEM Characterization of Gold Nanoclusters in TiO2(110)

2003 ◽  
Vol 792 ◽  
Author(s):  
V. Shutthanandan ◽  
Y. Zhang ◽  
C. M. Wang ◽  
J. S. Young ◽  
L. Saraf ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Gold Nanoclusters ◽  
Subsequent Annealing ◽  
Transmission Electron ◽  
Scanning Electron

ABSTRACTNucleation of gold nanoclusters in TiO2(110) single crystal using ion implantation and subsequent annealing were studied by Rutherford backscattering spectrometry /channeling (RBS/C), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Approximately 1000 Au2+/nm2 were implanted at room temperature in TiO2(110) substrates. TEM and SEM measurements reveal that rounded nanoclusters were formed during the implantation. In contrast, subsequent annealing in air for 10 hours at 1275 K promoted the formation of faceted (rectangular shaped) Au nanostructures in TiO2. RBS channeling measurements further reveled that Au atoms randomly occupied the host TiO2 lattice during the implantation. However, it appears that some Au atoms moved to the Ti lattice positions after annealing.

Epitaxial Growth and Stability of C49 TiSi2 ON Si(111).

1990 ◽  
Vol 198 ◽  
Author(s):  
Hyeongtag Jeon ◽  
J. W. Honeycutt ◽  
C. A. Sukow ◽  
T. P. Humphreys ◽  
R. J. Nemanich ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Metastable Phase ◽  
Plan View ◽  
Transmission Electron ◽  
Temperature Deposition ◽  
The Individual ◽  
Relationship Of

ABSTRACTEpitaxial TiSi2 films have been grown by molecular beam epitaxy (MBE) on atomically clean Si(111)-orientated substrates. The growth procedure involves the ambient temperature deposition of Ti films of 50Å thickness and annealing to 800°C. In situ low energy electron diffraction (LEED) and Auger electron spectroscopy (AES) techniques have been used to monitor the TiSi2 formation process. The epitaxial films have been identified as the C49 metastable phase by both Raman spectroscopy and electron diffraction. Plan view transmission electron microscopy shows three different connected island morphologies. The individual island structures are single crystal and are grown epitaxially with different crystallographic orientations. The orientational relationship of the largest islands is given by [3 1 1] C49 TiSi2//[112]Si and (130) C49 TiSi2//(l1 1)Si. High resolution transmission electron microscopy (HRTEM) cross-section shows a coherent interface extending over several hundred angstroms.

Techniques for Studying Nanoparticle Sintering by Plan-View In Situ Transmission Electron Microscopy

1998 ◽  
Vol 4 (3) ◽  
pp. 248-253 ◽  
Author(s):  
M. Yeadon ◽  
J.C. Yang ◽  
R.S. Averback ◽  
J.M. Gibson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal Substrate ◽  
Plan View ◽  
Supported Nanoparticles ◽  
Transmission Electron ◽  
Theoretical Predictions ◽  
Crystal Substrate

We discuss various techniques for the characterization of supported nanoparticles by in situ plan-view transmission electron microscopy. In particular, we discuss here mechanisms of image contrast formation by particles undergoing reorientation on the surface of a single crystal substrate. We consider reorientation by a variety of mechanisms including rotation, sintering and grain growth, and surface diffusion. Experimental observations are presented and the data compared with theoretical predictions.

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