Grain Boundaries In Diamond Films On Si(001)

1996 ◽  
Vol 466 ◽  
Author(s):  
D. Wittorf ◽  
C. L. Jia ◽  
W. Jäger ◽  
B. Grushko ◽  
K. Urban ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Small Angle ◽  
Large Angle ◽  
Diamond Films ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Dislocation Model ◽  
Crystal Lattices ◽  
Plan View ◽  
Resolution Electron

ABSTRACTGrain boundaries in [001]-oriented diamond films deposited on Si(001) by microwave-assisted chemical vapor deposition have been investigated in plan-view and cross-section samples using high-resolution electron microscopy. The poly-crystalline diamond films used in this study had large fractions of [001]-oriented grains with typical lateral dimensions of 2 μm at film thicknesses beyond 10 μm. Grains with growth orientations near (001) exhibit generally small-angle orientation deviations between their crystal lattices. Small-angle grain boundaries of symmetric and asymmetric geometry with misorientation angles below 15° are investigated in both [110]- and [001]-directions. It is found that the structures of such small-angle grain boundaries can be described by a dislocation model. These grain boundaries are on average parallel to the {110}-plane and contain in many cases micro-facets parallel to {lll}-planes. Large-angle grain boundaries with tilt angles up to 40° are also observed in interconnected films of smaller thickness. In all cases structural units with large open volumes and additional second phases are not found at the grain boundaries.

The effect of doping Ag on the microstructure of La2/3Sr1/3MnO3 films

2002 ◽  
Vol 17 (10) ◽  
pp. 2712-2719 ◽  
Author(s):  
Q. Zhan ◽  
R. Yu ◽  
L. L. He ◽  
D. X. Li ◽  
J. Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Grain Boundaries ◽  
Doping Level ◽  
Analytical Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
Plan View ◽  
Ag Doping ◽  
Low Field ◽  
Resolution Electron ◽  
Magnetic Spin

The microstructure of Ag-doped La2/3Sr1/3MnO3 (LSMO) thin films deposited on (001) LaAlO3 single-crystal substrates was systematically investigated in cross section and plan view by high-resolution electron microscopy and analytical electron microscopy. The results showed that the films deposited at 750 °C were perfectly epitaxial with or without Ag-doping. No Ag in the doped film was detected. On the other hand, the LSMO films deposited at 400 °C were less perfect. With increasing Ag-doping level, the shape of LSMO grains became irregular, and the grain size increased gradually. Large polycrystalline clusters consisting of LSMO, AgO, and Ag grains formed in the doped films, and the amount and size of them increased with increasing Ag-doping level. Ag existed at the LSMO grain boundaries in its elemental state. A growth process for the LSMO-Ag system is discussed based on the experimental results. The enhancement of the magnetic spin disorders at the grain boundaries and interfaces caused by doping Ag could result in an improvement of low-field magnetoresistance.

scholarly journals Microstructure and Nonstoichiometry of Barium Strontium Titanate thin films for dram Applications

1999 ◽  
Vol 574 ◽  
Author(s):  
S. Stemmer ◽  
S. K. Streiffer ◽  
N. D. Browning ◽  
A. I. Kingon
Keyword(s):  
Thin Films ◽  
Grain Boundaries ◽  
Boundary Segregation ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Barium Strontium ◽  
Resolution Electron ◽  
Electrical And Dielectric Properties ◽  
Bst Films ◽  
Electron Energy Loss

AbstractIn this paper we investigate the microstructural accommodation of nonstoichiometry in (BaxSr1-x)Ti1+yO3+Z thin films grown by chemical vapor deposition. Films with three different (Ba+Sr)/Ti ratios of 49/51 (y=0.04 in the notation of the formula above), of 48/52 (y = 0.08) and of 46.5/53.5 (y=0.15), were studied. High-resolution electron microscopy is used to study the microstructure of the BST films. High-spatial resolution electron energy-loss spectroscopy (EELS) is used to reveal changes in chemistry and local atomic environment both at grain boundaries and within grains as a function of titanium excess. We find an amorphous phase at the grain boundaries and grain boundary segregation of excess titanium in the samples with y=0.15. In addition, EELS is also used to show that excess titanium is being partially accommodated in the grain interior. Implications for the film electrical and dielectric properties are outlined.

Heteroepitaxial Diamond Formed on Silicon Wafer Observed by High Resolution Electron Microscopy

1994 ◽  
Vol 357 ◽  
Author(s):  
Jie Yang ◽  
Zhangda Lin ◽  
Li-Xin Wang ◽  
Sing Jin ◽  
Ze Zhang
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Diamond Films ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Cross Sectional ◽  
Diamond Crystals ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Hot Filament

AbstractDiamond films with high preferential orientation (111) on silicon (100) crystalline orientation substrates had been obtained by hot-filament chemical vapor deposition (HFCVD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and high-resolution cross-sectional transmission electron microscopy (HREM) are used to characterizate the structure and morphology of the synthesised diamond films. Diamond (111) plans had been local grown epitaxially on the Si(100) substrate observed by HREM. SEM photographes show that plane diamond crystals have been obtained.

HREM STUDIES OF THE SUPERCONDUCTING PHASE Tl2Ba2Ca2Cu3Ox

1989 ◽  
Vol 03 (04) ◽  
pp. 361-367
Author(s):  
J.G. ZHENG ◽  
J. CHEN ◽  
J.G. JIANG ◽  
Y.H. LIANG ◽  
S.Y. DING ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundaries ◽  
Large Angle ◽  
Amorphous State ◽  
High Resolution Electron Microscopy ◽  
Superconducting Phase ◽  
Nominal Composition ◽  
Resolution Electron ◽  
Superconducting Ceramics

The superconducting phase Tl 2 Ba 2 Ca 2 Cu 3 O x (Tl2223) has been identified in high-T c superconducting ceramics with nominal composition of Tl 2 Ba 2 Ca 2 Cu 3. The configurations of grains and grain boundaries have also been observed directly by high resolution electron microscopy [HREM]. The small angle grain boundaries are mixed with both translation and orientation characteristics. The boundary regions are nearly parallel to (100) to (010) in crystal state, While in amorphous state, they are nearly parallel to (001). There also exists large angle grain boundaries in TlBaCaCuO superconductor.

Grain Boundaries of Controlled Geometry in ZnO Films Grown by Chemical Vapor Deposition: Undoped and Bi -Doped Boundaries

1995 ◽  
Vol 401 ◽  
Author(s):  
I. Majid ◽  
Y. Liu ◽  
R. W. Balluffi ◽  
J. B. Vander Sande
Keyword(s):  
Grain Boundaries ◽  
Level Structure ◽  
Chemical Vapour ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Diffusion Method ◽  
Zno Films ◽  
Resolution Electron ◽  
Chemical Vapour Deposition Technique ◽  
Crystal Films

AbstractWe describe a chemical vapour deposition technique for the controlled growth of ZnO films, containing grain boundaries which are suitable for detailed atomic resolution studies. Using this technique, we have grown; (1) random polycrystalline, (2) highly textured polycrystalline and (3) nominally single crystal films Also, a technique for doping the grain boundaries in these specimens with Bi by an “in-diffusion” method is demonstrated. The grain boundary atomic level structure and chemistry is studied by means of High Resolution Electron Microscopy (HREM) and STEM/EDX microanalysis. Some results obtained from boundaries in textured polycrystalline films which have the c-axes in neighboring grains lined-up to ˜1 ° are described.

Growth defects in diamond films

1993 ◽  
Vol 8 (3) ◽  
pp. 473-479 ◽  
Author(s):  
D. Shechtman ◽  
J.L. Hutchison ◽  
L.H. Robins ◽  
E.N. Farabaugh ◽  
A. Feldman
Keyword(s):  
Vapor Deposition ◽  
Diamond Films ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Growth Direction ◽  
Nucleation Site ◽  
Growth Defects ◽  
Resolution Electron ◽  
Intersection Points ◽  
Type 3

Growth defects in diamond films grown by plasma-assisted chemical vapor deposition (CVD) were studied by high resolution electron microscopy. Several features of the microstructure were resolved and their importance to the growth of the diamond film was evaluated. The observations included various twin boundaries of the type ∑ = 3, as well as ∑ = 9, ∑ = 27, and ∑ = 81, which form by an interaction of lower order twins. These higher order boundaries are loci of intersection points of growing planes on two adjacent twins and can serve as an indicator for the local crystal growth direction. The central nucleation site for the growing planes in many cases can be traced back to a quintuplet twin point. A twin quintuplet has five re-entrant angles and thus serves as a preferred nucleation site for new planes as the crystal grows.

Finding the Right Problems: Some HREM Applications to Interfaces

1984 ◽  
Vol 42 ◽  
pp. 376-379
Author(s):  
D. Cherns
Keyword(s):  
Grain Boundaries ◽  
High Resolution Electron Microscopy ◽  
Boundary Structure ◽  
Atomic Structures ◽  
Grain Boundary Structure ◽  
Resolution Electron ◽  
Point To Point ◽  
The Right ◽  
New Generation ◽  
Better Than

The use of high resolution electron microscopy (HREM) to determine the atomic structure of grain boundaries and interfaces is a topic of great current interest. Grain boundary structure has been considered for many years as central to an understanding of the mechanical and transport properties of materials. Some more recent attention has focussed on the atomic structures of metalsemiconductor interfaces which are believed to control electrical properties of contacts. The atomic structures of interfaces in semiconductor or metal multilayers is an area of growing interest for understanding the unusual electrical or mechanical properties which these new materials possess. However, although the point-to-point resolutions of currently available HREMs, ∼2-3Å, appear sufficient to solve many of these problems, few atomic models of grain boundaries and interfaces have been derived. Moreover, with a new generation of 300-400kV instruments promising resolutions in the 1.6-2.0 Å range, and resolutions better than 1.5Å expected from specialist instruments, it is an appropriate time to consider the usefulness of HREM for interface studies.

High-resolution electron microscopy of nanostructured materials

1995 ◽  
Vol 53 ◽  
pp. 172-173
Author(s):  
M. José-Yacamán
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundaries ◽  
Nanostructured Materials ◽  
High Resolution Electron Microscopy ◽  
Hrem Image ◽  
Small Particles ◽  
Resolution Electron ◽  
Nanophase Materials

Electron microscopy is a fundamental tool in materials characterization. In the case of nanostructured materials we are looking for features with a size in the nanometer range. Therefore often the conventional TEM techniques are not enough for characterization of nanophases. High Resolution Electron Microscopy (HREM), is a key technique in order to characterize those materials with a resolution of ~ 1.7A. High resolution studies of metallic nanostructured materials has been also reported in the literature. It is concluded that boundaries in nanophase materials are similar in structure to the regular grain boundaries. That work therefore did not confirm the early hipothesis on the field that grain boundaries in nanostructured materials have a special behavior. We will show in this paper that by a combination of HREM image processing, and image calculations, it is possible to prove that small particles and coalesced grains have a significant surface roughness, as well as large internal strain.

Σ =13 tilt grain boundary in silicon bicrystal

1990 ◽  
Vol 48 (4) ◽  
pp. 562-563
Author(s):  
M.J. Kim ◽  
Y.L. Chen ◽  
R.W. Carpenter ◽  
J.C. Barry ◽  
G.H. Schwuttke
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Rotation Axis ◽  
Czochralski Method ◽  
High Resolution Electron Microscopy ◽  
Image Simulation ◽  
Simulation Techniques ◽  
Resolution Electron ◽  
The Common ◽  
Tilt Grain Boundary

The structure of grain boundaries (GBs) in metals, semiconductors and ceramics is of considerable interest because of their influence on physical properties. Progress in understanding the structure of grain boundaries at the atomic level has been made by high resolution electron microscopy (HREM) . In the present study, a Σ=13, (510) <001>-tilt grain boundary in silicon was characterized by HREM in conjunction with digital image processing and computer image simulation techniques.The bicrystals were grown from the melt by the Czochralski method, using preoriented seeds. Specimens for TEM observations were cut from the bicrystals perpendicular to the common rotation axis of pure tilt grain boundary, and were mechanically dimpled and then ion-milled to electron transparency. The degree of misorientation between the common <001> axis of the bicrystal was measured by CBED in a Philips EM 400ST/FEG: it was found to be less than 1 mrad. HREM was performed at 200 kV in an ISI-002B and at 400 kv in a JEM-4000EX.

scholarly journals Analysis of Stresses and Strains around Dislocations at Grain Boundaries by Quantitative High-Resolution Electron Microscopy

2006 ◽  
Vol 12 (S02) ◽  
pp. 894-895
Author(s):  
M Hytch ◽  
J-L Putaux ◽  
J Thibault
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundaries ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006

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