Crystal structure and epitaxial relationship of Ni4InGaAs2 films formed on InGaAs by annealing

2013 ◽  
Vol 31 (1) ◽  
pp. 012202 ◽  
Author(s):  
Ivana ◽  
Yong Lim Foo ◽  
Xingui Zhang ◽  
Qian Zhou ◽  
Jisheng Pan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Epitaxial Relationship ◽  
Relationship Of

High-resolution transmission electron microscopic investigations of molybdenum thin films on faceted α-Al2O3

2005 ◽  
Vol 38 (2) ◽  
pp. 260-265 ◽  
Author(s):  
Leonore Wiehl ◽  
Jens Oster ◽  
Michael Huth
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
Epitaxial Relationship ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
High Resolution Images ◽  
Α Al2o3 ◽  
Relationship Of

Epitaxially grown Mo films on a faceted corundum (α-Al2O3)mplane were investigated by transmission electron microscopy. Low- and high-resolution images were taken from a cross-section specimen cut perpendicular to the facets. It was possible to identify unambiguously the crystallographic orientation of these facets and explain the considerable deviation (∼10°) of the experimental interfacet angle, as measured with atomic force microscopy (AFM), from the expected value. For the first time, proof is given for a smooth \{10\bar{1}1\} facet and a curvy facet with orientation near to \{10\bar{1}\bar{2}\}. Moreover, the three-dimensional epitaxial relationship of an Mo film on a faceted corundummsurface was determined.

scholarly journals The crystal structure of a Polerovirus exoribonuclease-resistant RNA shows how diverse sequences are integrated into a conserved fold

2020 ◽  
Author(s):  
Anna-Lena Steckelberg ◽  
Quentin Vicens ◽  
David A. Costantino ◽  
Jay C. Nix ◽  
Jeffrey S. Kieft
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Rna Structures ◽  
Discrete Elements ◽  
Protein Coding ◽  
Sequence Elements ◽  
Conservation Patterns ◽  
Function Relationship ◽  
Relationship Of ◽  
Folded Rna

ABSTRACTExonuclease-resistant RNAs (xrRNAs) are discrete elements that block the progression of 5’ to 3’ exonucleases using specifically folded RNA structures. A recently discovered class of xrRNA is widespread in several genera of plant-infecting viruses, within both noncoding and protein-coding subgenomic RNAs. The structure of one such xrRNA from a dianthovirus revealed three-dimensional details of the resistant fold but did not answer all questions regarding the conservation and diversity of this xrRNA class. Here, we present the crystal structure of a representative polerovirus xrRNA that contains sequence elements that diverge from the previously solved structure. This new structure rationalizes previously unexplained sequence conservation patterns and shows interactions not present in the first structure. Together, the structures of these xrRNAs from dianthovirus and polerovirus genera support the idea that these plant virus xrRNAs fold through a defined pathway that includes a programmed intermediate conformation. This work deepens our knowledge of the structure-function relationship of xrRNAs and shows how evolution can craft similar RNA folds from divergent sequences.

scholarly journals Thermal Chemical Vapor Deposition of Epitaxial Rhombohedral Boron Nitride from Trimethylboron and Ammonia

2018 ◽  
Author(s):  
Laurent Souqui ◽  
Henrik Pedersen ◽  
Hans Högberg
Keyword(s):  
Chemical Vapor Deposition ◽  
Boron Nitride ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Epitaxial Relationship ◽  
Out Of Plane ◽  
Α Al2o3 ◽  
Favorable Conditions ◽  
Relationship Of ◽  
Rhombohedral Boron

Epitaxial rhombohedral boron nitride films were deposited on α-Al2O3(001) substrates by chemical vapor deposition, using trimethylboron, ammonia, and with a low concentration of silane in the growth flux. The depositions were performed at temperatures from 1200 to 1485 °C, pressures from 30 to 90 mbar and N/B ratios from 321 to 1286. The most favorable conditions for epitaxy were: a temperature of 1400 °C, N/B around 964, and pressures below 40 mbar. Analysis by thin film X-ray diffraction showed that most deposited films were polytype-pure epitaxial r-BN with an out-of-plane epitaxial relationship of r-BN[001]∥ w-AlN[001]∥ α-Al2O3[001] and with two in-plane relationships of r-BN[110]∥ w-AlN[110]∥ α-Al2O3[100] and r-BN[110]∥ w-AlN[110]∥ α-Al2O3[1̅00] due to twinning.

The process and mechanism of the GaN nanoparticles formed by nitridation of β-Ga2O3 crystal

2017 ◽  
Vol 31 (10) ◽  
pp. 1750108 ◽  
Author(s):  
Xiao-Jun Cui ◽  
Liang-Ling Wang
Keyword(s):  
Vapor Deposition ◽  
Surface Defect ◽  
Chemical Vapor ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
X Ray ◽  
Diffraction Peaks ◽  
Relationship Of ◽  
Gan Film

The process of conversion from [Formula: see text]-Ga2O3 single crystal to gallium nitride (GaN) in an atmosphere of NH3 by chemical vapor deposition is investigated. The surface morphology and microstructure of the GaN nanoparticles are observed by scanning electron microscope, which indicates that the growth of GaN is via the Volmer–Weber mechanism. The [Formula: see text]-Ga2O3 is firstly evaporated at high temperature to form the porous layer, followed by the surface-defect induced GaN nucleation formation. The crystalline structure and epitaxial relationship of the GaN nanoparticles are investigated by X-ray diffraction (XRD) via [Formula: see text]–[Formula: see text], showing GaN (0002) and (0004) diffraction peaks in the XRD spectra. It is concluded that the polycrystalline GaN film with hexagonal structure has a strong c-axis preferential orientation.

Strain relaxation and epitaxial relationship of perylene overlayer on Ag(110)

2018 ◽  
Vol 148 (21) ◽  
pp. 214702 ◽  
Author(s):  
Nataliya Kalashnyk ◽  
Lionel Amiaud ◽  
Céline Dablemont ◽  
Anne Lafosse ◽  
Kirill Bobrov ◽  
...  
Keyword(s):  
Strain Relaxation ◽  
Epitaxial Relationship ◽  
Relationship Of

Nd7,33Ta8O28CI6 — ein Zwischenprodukt des thermischen Abbaus von Nd2Ta2O7Cl2: Präparation, Struktur und magnetische Eigenschaften / Nd7,33Ta8O28Cl6 — an Intermediate Product of the Thermal Decomposition of Nd2Ta2O7Cl2: Preparation, Crystal Structure and Magnetic Properties

1988 ◽  
Vol 43 (12) ◽  
pp. 1567-1574 ◽  
Author(s):  
U. Schaffrath ◽  
R. Gruehn
Keyword(s):  
Crystal Structure ◽  
Thermal Decomposition ◽  
Magnetic Properties ◽  
Calculated Data ◽  
Chemical Transport ◽  
Structure Type ◽  
Magnetic Susceptibilities ◽  
Relationship Of ◽  
The Relationship ◽  
Preparative Route

Abstract Single crystals of the new oxochlorotantalate Nd7.33Ta8O28Cl6, could be obtained only by chemical transport reactions (T2 → T1; T2 - 1000 °C, T, = 900 °C) with mixtures of Cl2/TaCl5 as transport agent. NdTaO4 was chosen as the starting material. A direct preparative route to Nd7.33Ta8O28Cl6 from binary and ternary components, however, was not successful. Nd7.33Ta8O28Cl6 , crystallizes in the space group Cmmm with a = 10.3381(8) Å, b = 18.865(1) Å, c - 3.9152(3) A; Z = 1. The structure was refined to R - 4.42%, R w = 2.76%. Main building units are pairs of edge-sharing TaO6 -octahedra which are connected with threefold capped trigonal prisms around Nd. Especially remarkable is one Nd position with an occupation factor of 0.833. The relationship of this new structure type with Nd2Ta2O7Cl2 is considered. Furthermore, we have measured the magnetic susceptibilities of both Nd-compounds in a temperature range from 3,6 to 251,3 K. The results are compared with calculated data.

Microstructural development of BaTiO3 powders synthesized by aqueous methods

1996 ◽  
Vol 11 (6) ◽  
pp. 1325-1328 ◽  
Author(s):  
L. Zhao ◽  
A. T. Chien ◽  
F. F. Lange ◽  
J. S. Speck
Keyword(s):  
Electron Microscopy ◽  
Lattice Mismatch ◽  
Anatase Tio2 ◽  
Microstructural Development ◽  
Complete Conversion ◽  
Epitaxial Relationship ◽  
Tio2 Particles ◽  
Transmission Electron ◽  
Alkaline Conditions ◽  
Relationship Of

The hydrothermal growth of perovskite BaTiO3 powders has been studied by transmission electron microscopy. The growth is carried out under high alkaline conditions (pH — 14) achieved with Ba(OH)2. Anatase (TiO2) is used as a titanium source. The perovskite BaTiO3 nucleates heterogeneously on anatase TiO2 particles with an epitaxial relationship of (001)TiO2 ‖ (001)BaTiO3 and [010]TiO2 ‖ [010]BaTiO3. This epitaxial relationship preserves the parallel alignment of the oxygen octahedra between the structures. A mosaic misorientation between (001)TiO2 and (001)BaTiO3 along 〈110〉 is seen in this relationship due to the lattice mismatch between TiO2 and BaTiO3. After complete conversion of the anatase to BaTiO3, the BaTiO3 particles develop into {111} octahedrons with ∼10 nm {001} and {110} microfacets on the {111} faces. This evolution suggests that {111} becomes the stable crystallographic facet for BaTiO3 under highly alkaline conditions.

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