Atomic Observation of the Sublimation Process of the Pb (111) Surface

2003 ◽  
Vol 10 (02n03) ◽  
pp. 455-459 ◽  
Author(s):  
T. Tanigaki ◽  
H. Suzuki ◽  
Y. Kimura ◽  
C. Kaito ◽  
Y. Saito
Keyword(s):  
Electron Microscope ◽  
Video Recording ◽  
Carbon Film ◽  
Atomic Layer ◽  
Carbon Layer ◽  
Sublimation Process ◽  
Step Flow ◽  
Transmission Electron ◽  
Evaporation Technique ◽  
Gas Evaporation Technique

The dynamic behavior of the sublimation process using ultrafine Pb particles produced by the gas evaporation technique was examined at the level of atomic resolution using a transmission electron microscope equipped with a real-time video-recording system. The ultrafine Pb particles coated with a carbon layer with a thickness of the order of 5 nm were prepared in the electron microscope by heating particles on carbon film at 300°C. Sublimation of the Pb particle covered with the carbon layer took place above 470°C, which is slightly higher than the melting point of Pb. Sublimation occurred at the surface with a higher surface energy. The sublimation process of the (111) surface was clearly observed at an atomic level. It was found that two- or four-atomic-layer step flow was observed at the (111) surface. At the (111) surface between the stacking faults, two-layer and successive one-layer sublimation occurred.

scholarly journals Comparison of the Growth and Thermal Properties of Nonwoven Polymers after Atomic Layer Deposition and Vapor Phase Infiltration

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1028
Author(s):  
Laura Keskiväli ◽  
Pirjo Heikkilä ◽  
Eija Kenttä ◽  
Tommi Virtanen ◽  
Hille Rautkoski ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Electron Microscope ◽  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Scanning Transmission Electron Microscope ◽  
Scanning Calorimetry ◽  
Polymeric Surfaces ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Scanning Transmission

The growth mechanism of Atomic Layer Deposition (ALD) on polymeric surfaces differs from growth on inorganic solid substrates, such as silicon wafer or glass. In this paper, we report the growth experiments of Al2O3 and ZnO on nonwoven poly-L-lactic acid (PLLA), polyethersulphone (PES) and cellulose acetate (CA) fibres. Material growth in both ALD and infiltration mode was studied. The structures were examined with a scanning electron microscope (SEM), scanning transmission electron microscope (STEM), attenuated total reflectance-fourier-transform infrared spectroscopy (ATR-FTIR) and 27Al nuclear magnetic resonance (NMR). Furthermore, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis were used to explore the effect of ALD deposition on the thermal properties of the CA polymer. According to the SEM, STEM and ATR-FTIR analysis, the growth of Al2O3 was more uniform than ZnO on each of the polymers studied. In addition, according to ATR-FTIR spectroscopy, the infiltration resulted in interactions between the polymers and the ALD precursors. Thermal analysis (TGA/DSC) revealed a slower depolymerization process and better thermal resistance upon heating both in ALD-coated and infiltrated fibres, more pronounced on the latter type of structures, as seen from smaller endothermic peaks on TA.

X-Ray Microanalysis Combined with Monte Carlo Simulation for the Analysis of Layered Thin Films: The Case of Carbon Contamination

2009 ◽  
Vol 15 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Aldo Armigliato ◽  
Rodolfo Rosa
Keyword(s):  
Monte Carlo ◽  
Carbon Film ◽  
Sample Surface ◽  
Scanning Transmission Electron Microscope ◽  
Carbon Layer ◽  
Monte Carlo Code ◽  
X Ray ◽  
Transmission Electron ◽  
The Monte Carlo Method ◽  
Scanning Transmission

AbstractA previously developed Monte Carlo code has been extended to the X-ray microanalysis in a (scanning) transmission electron microscope of plan sections, consisting of bilayers and triple layers. To test the validity of this method for quantification purposes, a commercially available NiOx (x ∼ 1) thin film, deposited on a carbon layer, has been chosen. The composition and thickness of the NiO film and the thickness of the C support layer are obtained by fitting to the three X-ray intensity ratios I(NiK)/I(OK), I(NiK)/I(CK), and I(OK)/I(CK). Moreover, it has been investigated to what extent the resulting film composition is affected by the presence of a contaminating carbon film at the sample surface. To this end, the sample has been analyzed both in the (recommended) “grid downward” geometry and in the upside/down (“grid upward”) situation. It is found that a carbon contaminating film of few tens of nanometers must be assumed in both cases, in addition to the C support film. Consequently, assuming the proper C/NiOx/C stack in the simulations, the Monte Carlo method yields the correct oxygen concentration and thickness of the NiOx film.

Observation of Redshifts of Photoluminescence from Thin Films Assembled by CuCl Nanoclusters

1997 ◽  
Vol 11 (06) ◽  
pp. 275-281
Author(s):  
Bingyou Miao ◽  
Jianmin Hong ◽  
Pingping Chen ◽  
Xiaoli Yuan ◽  
Min Han ◽  
...  
Keyword(s):  
Thin Films ◽  
Quantum Confinement ◽  
Phonon Coupling ◽  
Transmission Electron ◽  
Two Samples ◽  
Evaporation Technique ◽  
The Mean ◽  
Quartz Substrates ◽  
Cucl Nanocrystals ◽  
Gas Evaporation Technique

Two samples of thin films, assembled by CuCl nanoclusters, have been prepared by the gas evaporation technique. The CuCl nanoclusters were deposited on monocrystalline silicon and quartz substrates and then coated with a layer of NaCl to prevent oxidation of the CuCl nanoclusters. From transmission electron microscope and selected area diffraction, it is clear that the two samples consist of CuCl nanocrystals and Cu aggregates and the mean diameters are about 3 nm and 6 nm. From the absorption and photoluminescence (PL) spectra of the two samples carried out at ~300 K, we found that the peaks of exciton absorption do not show up and luminescence peaks shift to lower energies, possibly due to the strong coupling between exciton and phonon. At 77 K, the PL peaks of excitons broadened by exciton–phonon coupling have been observed, in approximate agreement with the values calculated by the quantum confinement model. The broad peaks of emission from trapped states or bands have also been observed at 77 K. In addition, the interaction between exciton and phonon is stronger in the sample with mean diameter about 3 nm according to a larger broadening and redshift of the PL peak from excitons, in qualitative agreement with theoretical prediction.

Surface study by UHV electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 458-459
Author(s):  
K. Yagi ◽  
K. Takayanagi ◽  
K. Kobayashi ◽  
N. Osakabe ◽  
Y. Tanishiro ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Film Growth ◽  
Atomic Layer ◽  
Chemical Compositions ◽  
Surface Phenomena ◽  
Transmission Electron ◽  
In Situ Deposition ◽  
Complementary Role ◽  
Atomically Flat

Recent advances of UHV techniques, LEED, RHEED and AES, arose a surge of interest on the surface of solids. These techniques reveal structures and chemical compositions at the mono-atomic or mono-molecular level. All of them, however, are devoid of detailed topographic informations, although some efforts to introduce the scanning techniques have been done[l]. Transmission electron microscopy of high resolution should play a complementary role to these techniques. No attempt, however, has been done previously to use it to such a purpose. This was because it was difficult to get and keep clean surfaces in the poor vacuum at 1x10-5 Torr level of the conventional electron microscope.The present paper reports observations of surface phenomena of one or two atomic layer level using a UHV JEM 100B electron microscope (10-8 -10-10Torr), recently developed for insitu thin film growth studies[2]. Atomically flat (111) surfaces of Ag, Pd, Au and Cu were prepared by in- situ deposition at 150-350°C on M0S2, graphite and MgO. Air Cleaved thin films of MoS2 and graphite were preheated to 800°C to get clean surfaces[3].

Transmission Electron Microscopy study of lead sulfide whiskers

1989 ◽  
Vol 47 ◽  
pp. 444-445
Author(s):  
S.A. Mansour ◽  
R. Scholz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Lead Sulfide ◽  
Carbon Film ◽  
Flame Temperature ◽  
High Resolution Electron Microscopy ◽  
Spiral Coil ◽  
Transmission Electron

This paper describes a transmission electron microscopy (TEM) study of the structure and growth mechanism of lead sulfide (PbS) whiskers. PbS whiskers were grown inside the stainless steel nozzle of a kerosene burner. The nozzle had a 0.5 mm aperture, and was fitted with an Al-spiral coil to filter kerosene impurities. The burner was operated continuously for four weeks at a kerosene pressure of 2-3 bars and a flame temperature of about 350°C before the nozzle clogged. A thick black deposit of fine PbS whiskers was found inside the nozzle.TEM specimens were prepared by ultrasonically suspending the fine black powder in alcohol. The suspended particles were deposited on a perforated carbon film supported on a copper grid, and examined with a JEM-1200EX transmission electron microscope operated at 120kV accelerating voltage. A JEM-4000EX transmission electron microscope was used for high resolution electron microscopy.Fig. 1. shows an EM micrograph of typical PbS whiskers. Each appears to have a high-contrast core encapsulated in a lower contrast shell. The electron diffraction pattern of a single whisker protruding over a hole in the carbon film is shown in Fig. 2.

scholarly journals HIGH RESOLUTION IMAGING OF BORON DISTRIBUTION ON DIAMOND FILM USING ENERGY FILTERED TEM

2016 ◽  
Vol 2 (1) ◽  
pp. 16
Author(s):  
A. Dimyati ◽  
S. Purwanto ◽  
R. Iskandar
Keyword(s):  
Diamond Film ◽  
Imaging Techniques ◽  
Carbon Film ◽  
Chemical Vapor ◽  
Carbon Layer ◽  
High Resolution Imaging ◽  
Si Substrate ◽  
Transmission Electron ◽  
Resolution Imaging ◽  
Boron Distribution

<p class="TRANSAffiliation"><span>The main difficulty in investigation of thin film systems is the lack of capability to get detail information of the material in nano level due to the low resolution of conventional imaging techniques such as SEM, SIMS etc. In this work Electron Spectroscopy Imaging (ESI) in energy filtered transmission electron microscope (EFTEM) was used to produce a real image of  boron distribution in a diamond film deposited on (111) Si by chemical vapor deposition. The result revealed the layer consists of 1.3 µm thick diamond structured carbon film adjacent to Si substrate and 120 nm amorph carbon layer on top most surface. Boron atoms were distributed uniformly in both layer, however slight higher concentration in the second layer is observed. There was obviously no grain boundary enrichment of Boron atoms observed.</span></p>

Nanometer-area diffraction of small iron crystallites in single crystalline Fe-MgO composite films

1988 ◽  
Vol 46 ◽  
pp. 706-707
Author(s):  
N. Tanaka ◽  
K. Mihama ◽  
H. Ou ◽  
J.M. Cowley
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Carbon Film ◽  
Composite Films ◽  
High Resolution Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Specimen Preparation ◽  
Single Crystalline ◽  
Transmission Electron

Nanometer-sized iron(Fe) crystallites can be prepared in a single crystalline magnesium oxide(MgO) film by a simultaneous vacuum deposition of Fe and MgO. The crystallites are grown epitaxially and almost coherently in the film, the orientation being (001) [110]Fe//(001)[100]MgOand (011) [100]Fe//(001) [100]MgO. A heat treatment of the as-grown composite films at 500-1000°C brings about a phase-transformation from α -iron(b.c.c.) to γ -iron(f.c.c.). In the present study, the phase-transformation and the structure of the γ-iron crystallites are studied by nanometer-area electron diffraction(nanodiffraction) in TEM and STEM as well as high-resolution electron microscopy.The specimens were single crystalline Fe-MgO composite films prepared on a NaCl (001 ) surface by co-evaporation of Fe and MgO. The films were separated from the substrate in water and mounted on a perforated carbon film. Nanodiffraction in TEM was performed in a 200 kV transmission electron microscope(JEM- 2000FX)2 and that in STEM3was carried out in a 100 kV scanning transmission electron microscope (VG-HB5) equipped with a specimen-preparation chamber.

Structure and symmetry of CaFeTi2O6 perovskite

1995 ◽  
Vol 53 ◽  
pp. 364-365
Author(s):  
Nan Yao ◽  
Alexandra Navrotsky ◽  
Kurt Leinenweber
Keyword(s):  
Electron Microscope ◽  
Liquid Nitrogen ◽  
Transmission Electron Microscope ◽  
Point Group ◽  
Carbon Film ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Specimen Holder ◽  
Transmission Electron ◽  
Calcium Iron

A new calcium iron (II) titanate ordered perovskite (CaFeTi2O6) was recently synthesized from an equimolar mixture of CaTiO3 and FeTiO3 at 12-15 GPa and 1200-1400 °C. In the present paper, we discuss the structure and symmetry studies of this new compound CaFeTi2O6 using CBED and HREM techniques. The CaFeTi2O6 powder sample was crushed to small fragments with an agate mortar and pestle under purified methanol. A drop of the resulting suspension was placed on a copper grid coated with holey-carbon film. CBED and HREM studies were performed on a Philips-CM20 ST transmission electron microscope equipped with a double tilt, liquid-nitrogen-cooled specimen holder under moderate vacuum conditions over the range from 10-6-10-7 Torr. CBED makes it possible to examine the diffraction symmetry of key orientations of the crystal and therefore determine the point-group symmetry of the crystal. This information, along with the dynamic extinction information on systematic absences, can be used to determine the crystallographic space group uniquely.

Growth and microstructure of Cd1-xZnxS films deposited by hot-wall evaporation technique

1990 ◽  
Vol 48 (4) ◽  
pp. 700-701
Author(s):  
S. Chaudhuri ◽  
A. Dhar ◽  
A.K. Pal
Keyword(s):  
Electron Microscope ◽  
Cadmium Sulphide ◽  
Zinc Sulphide ◽  
Window Layer ◽  
Transmission Electron ◽  
Zn Content ◽  
Recent Developments ◽  
Evaporation Technique ◽  
Cadmium Zinc ◽  
Substrate Source

Recent developments in the field of solar photovaltaic technology with CdS as window layer indicated that Cd1-x Znx S is more suitable as the window layer because its propeerties may be tailored by simply adjusting the Zn content. It is known that the band gap of (Cd, Zn) S increases linearly with increasing Zn in the film.We report here our studies on the growth and microstructure of thin films of cadmium zinc sulphide (Cd1-xZnxS) with the values of x in the range (0<x<0.27). Films were deposited by coevaporation of cadmium sulphide and zinc sulphide by the hot wall evaporation. Three different substrates (NaCl, KCl and LiF) were used for deposition of films in the thickness range 70 - 90 nanometer. The substrate, source and hot wall temperatures were 510 K, 1170 K and 480 K respectively.The microstructure of the films (fig. 1 ,2,3) were observed by transmission electron microscope (Hitachi H 600) and scanning electron microscope (Hitachi S-2300).

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