scholarly journals Stabilization and Acidic Dissolution Mechanism of Single-Crystalline ZnO(0001) Surfaces in Electrolytes Studied by In-Situ AFM Imaging and Ex-Situ LEED

Langmuir ◽  
2008 ◽  
Vol 24 (10) ◽  
pp. 5350-5358 ◽  
Author(s):  
Markus Valtiner ◽  
Sergiy Borodin ◽  
Guido Grundmeier
Keyword(s):  
Ex Situ ◽  
Dissolution Mechanism ◽  
Single Crystalline ◽  
Afm Imaging ◽  
Acidic Dissolution

In-situ AFM study of the crystallization and pH-dependent stability of ZnO(0001)-Zn surfaces

2007 ◽  
Vol 1035 ◽  
Author(s):  
Markus Valtiner ◽  
Guido Grundmeier
Keyword(s):  
Electrolyte Solutions ◽  
Ex Situ ◽  
Chemical Cleaning ◽  
Single Crystalline ◽  
Afm Imaging ◽  
Wide Range ◽  
Wet Chemical ◽  
Ph Dependent ◽  
Crystalline Surfaces

AbstractPolar ZnO(0001)-Zn surfaces can be prepared as very well defined and single crystalline surfaces by hydroxide stabilization simply by introducing hydroxides via a wet chemical cleaning step. Within this proceeding we present an in-situ AFM imaging of the crystallization process. The pH dependent stability of the resulting hydroxide-stabilized surfaces was further investigated by means of an ex-situ LEED approach. These investigations show, that it is possible to obtain high quality single crystalline ZnO(0001)-Zn surfaces in a simple way. Moreover, these surfaces turned out to be very stable within a wide range of pH values between 11 and 3 of NaClO4 based 1mM electrolyte solutions.

In-situ and ex-situ AFM imaging of μN load indents on silicate glass/alumina interfaces

1996 ◽  
Vol 54 ◽  
pp. 660-661
Author(s):  
A. V. Zagrebelny ◽  
E. T. Lilleodden ◽  
J. C. Nelson ◽  
S. Ramamurthy ◽  
C. B. Carter
Keyword(s):  
Single Crystal ◽  
Silicate Glass ◽  
Small Volume ◽  
Ex Situ ◽  
Surface Roughening ◽  
Mechanistic Approach ◽  
Afm Imaging ◽  
Indentation Analysis ◽  
Single Crystal Sapphire

Contact which only involves a small volume of material is becoming increasingly important to many industries including micromachines, microelectronics, and magnetic recording. The ability to characterize surface roughening on the micro- and nanoscopic scale is invaluable in understanding microplasticity due to indentation, scratches, wear, fatigue and epitactic mismatch. It has been demonstrated that AFM studies are appropriate for developing a mechanistic approach to μN load indentation analysis since they allow deformation volumes and residual depths to be measured and characterized directly and unambiguously.In the present study, interfaces between silicate glass and single-crystal α-Al2O3 have been studied using AFM and nanoindentation. The interfaces between the glass and the crystalline grains were prepared by growing films of anorthite (CaAl2Si2O8) composition with thickness ranging 100-200 nm on single-crystal sapphire substrates of {1120} (A-plane) and {1102} (R-plane) crystallographic orientations by pulsed-laser deposition (PLD). Some specimens were subjected to heat treatments in a conventional box furnace causing films to dewet the substrates. Fig. 1 shows schematically the morphology of the dewetted film which has resulted in the formation of distinctive islands, 0.5-2 μm in size. Both types of specimens were tested with two different micro/nanomechanical testers.

In-Situ Measurements of Stress during Electrodeposition of Copper Nanofilms: Surface and Grain-Boundary Migration of Atoms and the Effect of Chloride Ions

2018 ◽  
Vol MA2018-01 (32) ◽  
pp. 1980-1980
Author(s):  
Joe A. Murphy ◽  
Catherine Lenihan ◽  
Maria Rybalchenko ◽  
Nathan Quill ◽  
Robert P. Lynch ◽  
...  
Keyword(s):  
Growth Rate ◽  
Grain Size ◽  
Steady State ◽  
Tensile Stress ◽  
Growth Rates ◽  
Ex Situ ◽  
Stress Measurements ◽  
Afm Imaging ◽  
State Stress

Electrodeposited metal films are often in a state of stress and this has been the subject of extensive experimental investigation and theoretical analysis1-4. We have been measuring stress development in situ during electrodeposition and correlating the results with in-situ AFM imaging during electrodeposition under similar conditions. In this paper we present results on the early stages of copper deposition from acidic CuSO4 electrolytes with and without chloride as an additive. To examine the effect of growth rate, sequential galvanostatic depositions were carried out (after an initial potentiostatic deposition of a thin layer of copper) over a relatively large range of growth rates (from 0.22 nm s-1 to 6.9 nm s-1) in additive-free electrolyte. At low growth rates, steady state stress was compressive. As growth rate was increased, the stress became less compressive and eventually became tensile. Crossover from compressive to tensile stress occurred at a growth rate of ~1 nm s-1. Both in-situ AFM imaging during deposition and ex-situ SEM imaging were used to characterise the evolution of grain size during the sequence of galvanostatic depositions used in the stress measurements. In general, grain size increased with continued deposition but eventually reached a constant value. Simulations based on Chason’s kinetic model3 gave a good fit of our experimental stress measurements in the region of constant grain size (~970 nm). The parameters from this fit were then used to model the steady state stress as a function growth rate and grain size. The values predicted by the model are plotted against the values from the experimental measurements in Figure 1. It can be seen that there is good agreement between model and experiment. The effect of added chloride in the electrolyte was also investigated. Even at low concentrations (< 1 ppm), the presence of chloride considerably reduced the tensile stress. Chloride-free and chloride-containing electrolytes also showed very different behaviours after interruption of electrodeposition. In chloride-free electrolyte, the tensile steady-state stress observed during deposition changed to compressive stress on interruption of the deposition. However, in chloride-containing electrolyte, the stress became even more tensile on interruption of deposition. Our experimental results on the change from one type of behaviour to the other as the chloride concentration was increased will be described and possible mechanisms will be discussed. References O.E. Kongstein, U. Bertoci and G.R. Stafford, J. Electrochem. Soc. 152, C116 (2005). S. Ahmed, T.T. Ahmed, M. O'Grady, S. Nakahara and D.N. Buckley, J. Applied Physics 103, (2008). E. Chason, Thin Solid Films 526, 1 (2012). E. Chason, A. Engwall, F. Pei, M. Lafouresse, U. Bertocci, G. Stafford, J.A. Murphy, C. Lenihan and D.N. Buckley, J. Electrochem. Soc. 160, D3285 (2013) Figure 1

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

1989 ◽  
Vol 47 ◽  
pp. 462-463
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

Atomic Layer Deposition of LiF and Lithium Ion Conducting (AlF3)(LiF)x Alloys Using Trimethylaluminum, Lithium Hexamethyldisilazide and Hydrogen Fluoride

2017 ◽  
Author(s):  
Younghee Lee ◽  
Daniela M. Piper ◽  
Andrew S. Cavanagh ◽  
Matthias J. Young ◽  
Se-Hee Lee ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Atomic Layer ◽  
Mass Gain ◽  
Alloy Film ◽  
Ex Situ ◽  
X Ray ◽  
Layer Deposition ◽  
Ion Conducting ◽  
Good Agreement

<div>Atomic layer deposition (ALD) of LiF and lithium ion conducting (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloys was developed using trimethylaluminum, lithium hexamethyldisilazide (LiHMDS) and hydrogen fluoride derived from HF-pyridine solution. ALD of LiF was studied using in situ quartz crystal microbalance (QCM) and in situ quadrupole mass spectrometer (QMS) at reaction temperatures between 125°C and 250°C. A mass gain per cycle of 12 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C and decreased at higher temperatures. QMS detected FSi(CH<sub>3</sub>)<sub>3</sub> as a reaction byproduct instead of HMDS at 150°C. LiF ALD showed self-limiting behavior. Ex situ measurements using X-ray reflectivity (XRR) and spectroscopic ellipsometry (SE) showed a growth rate of 0.5-0.6 Å/cycle, in good agreement with the in situ QCM measurements.</div><div>ALD of lithium ion conducting (AlF3)(LiF)x alloys was also demonstrated using in situ QCM and in situ QMS at reaction temperatures at 150°C A mass gain per sequence of 22 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C. Ex situ measurements using XRR and SE showed a linear growth rate of 0.9 Å/sequence, in good agreement with the in situ QCM measurements. Stoichiometry between AlF<sub>3</sub> and LiF by QCM experiment was calculated to 1:2.8. XPS showed LiF film consist of lithium and fluorine. XPS also showed (AlF<sub>3</sub>)(LiF)x alloy consists of aluminum, lithium and fluorine. Carbon, oxygen, and nitrogen impurities were both below the detection limit of XPS. Grazing incidence X-ray diffraction (GIXRD) observed that LiF and (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film have crystalline structures. Inductively coupled plasma mass spectrometry (ICP-MS) and ionic chromatography revealed atomic ratio of Li:F=1:1.1 and Al:Li:F=1:2.7: 5.4 for (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film. These atomic ratios were consistent with the calculation from QCM experiments. Finally, lithium ion conductivity (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film was measured as σ = 7.5 × 10<sup>-6</sup> S/cm.</div>

A New Method of Wafer Level Plan View TEM Sample Preparation by DualBeam

2008 ◽  
Author(s):  
Hyoung H. Kang ◽  
Michael A. Gribelyuk ◽  
Oliver D. Patterson ◽  
Steven B. Herschbein ◽  
Corey Senowitz
Keyword(s):  
Sample Preparation ◽  
Ex Situ ◽  
Wafer Level ◽  
Cross Sectional ◽  
Plan View ◽  
Manufacturing Line ◽  
Transmission Electron ◽  
Thin Lamella ◽  
Preparation Techniques

Abstract Cross-sectional style transmission electron microscopy (TEM) sample preparation techniques by DualBeam (SEM/FIB) systems are widely used in both laboratory and manufacturing lines with either in-situ or ex-situ lift out methods. By contrast, however, the plan view TEM sample has only been prepared in the laboratory environment, and only after breaking the wafer. This paper introduces a novel methodology for in-line, plan view TEM sample preparation at the 300mm wafer level that does not require breaking the wafer. It also presents the benefit of the technique on electrically short defects. The methodology of thin lamella TEM sample preparation for plan view work in two different tool configurations is also presented. The detailed procedure of thin lamella sample preparation is also described. In-line, full wafer plan view (S)TEM provides a quick turn around solution for defect analysis in the manufacturing line.

PROPUESTA DE CONSERVACIÓN DE TRES ESPECIES MEXICANAS DE PICEA EN PELIGRO DE EXTINCIÓN

2015 ◽  
Vol 38 (3) ◽  
pp. 235 ◽  
Author(s):  
Eduardo Mendoza-Maya ◽  
Judith Espino-Espino ◽  
Carmen Z. Quiñones-Pérez ◽  
Celestino Flores-López ◽  
Christian Wehenkel ◽  
...  
Keyword(s):  
Ex Situ

Picea mexicana Martínez, P. chihuahuana Martínez y P. martinezii Patterson son especies endémicas de México en peligro de extinción. Se presenta una síntesis de su situación actual y una propuesta de manejo para su conservación in situ y ex situ, con base en la diversidad y estructura genética de las poblaciones y la ubicación de las áreas en donde se predice existirá el hábitat climático que les es propicio en el futuro (años 2030, 2060 y 2090; al promediar los modelos Canadiense, Hadley y Geofísica de Fluidos con escenarios de emisiones A y B). Para la conservación in situ se plantea la protección, el incremento de la diversidad genética y la expansión de las tres únicas poblaciones de P. mexicana, las cuatro únicas de P. martinezii y ocho poblaciones designadas prioritarias de las 40 poblaciones de P. chihuahuana, mediante la plantación de individuos originados de otras poblaciones hasta alcanzar un tamaño mínimo de población genéticamente viable (entre 1035 a 3836 individuos). Para la conservación ex situ se propone el establecimiento de poblaciones en sitios fuera del rango de distribución natural de las especies, en donde se ha proyectado que ocurrirá el clima que les es propicio, con al menos 3606 individuos de P. mexicana en el volcán Cofre de Perote, Veracruz; 2431 individuos de P. chihuahuana en el municipio de Guanaceví, Durango; y 3092 individuos de P. martinezii en la región de Tlatlauquitepec, Puebla, con plantas originadas de una mezcla de semillas colectadas de árboles al azar de poblaciones específicas.

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