X-Ray Characterization of the Lattice Perfection of Heteroepitaxial SIS Structures

2007 ◽  
Vol 131-133 ◽  
pp. 619-624 ◽  
Author(s):  
P. Zaumseil ◽  
G. Weidner ◽  
T. Schroeder
Keyword(s):  
Molecular Beam ◽  
Structural Defects ◽  
Crystallographic Structure ◽  
Type B ◽  
X Ray Diffraction ◽  
X Ray ◽  
High K ◽  
Cap Layer ◽  
High K Materials

The crystallographic structure of semiconductor - insulator - semiconductor (SIS) structures consisting of a Si(111) substrate, Pr2O3 and Y2O3 insulating high-k materials, and Si cap layer was characterized by a combination of X-ray pole figure measurement and conventional X-ray diffraction. Oxide and Si cap layer were grown by molecular beam epitaxy and have the same 111 lattice orientation as the substrate. It is shown that the oxide layers grow in a type B stacking orientation only, while the epi-layer exhibits exclusively the same type A orientation as the substrate. A small fraction of the epi-Si lattice was identified with 511 netplanes parallel to the surface. TEM investigations identify these areas as structural defects between Si grains of differing stacking sequence.

scholarly journals Photoreversible interconversion of a phytochrome photosensory module in the crystalline state

2019 ◽  
Vol 117 (1) ◽  
pp. 300-307 ◽  
Author(s):  
E. Sethe Burgie ◽  
Jonathan A. Clinger ◽  
Mitchell D. Miller ◽  
Aaron S. Brewster ◽  
Pierre Aller ◽  
...  
Keyword(s):  
Single Crystal ◽  
Blue Light ◽  
Green Light ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Major Barrier ◽  
X Ray ◽  
Spectroscopic Analyses ◽  
Serial Femtosecond Crystallography

A major barrier to defining the structural intermediates that arise during the reversible photointerconversion of phytochromes between their biologically inactive and active states has been the lack of crystals that faithfully undergo this transition within the crystal lattice. Here, we describe a crystalline form of the cyclic GMP phosphodiesterases/adenylyl cyclase/FhlA (GAF) domain from the cyanobacteriochrome PixJ inThermosynechococcus elongatusassembled with phycocyanobilin that permits reversible photoconversion between the blue light-absorbing Pb and green light-absorbing Pg states, as well as thermal reversion of Pg back to Pb. The X-ray crystallographic structure of Pb matches previous models, including autocatalytic conversion of phycocyanobilin to phycoviolobilin upon binding and its tandem thioether linkage to the GAF domain. Cryocrystallography at 150 K, which compared diffraction data from a single crystal as Pb or after irradiation with blue light, detected photoconversion product(s) based on Fobs− Fobsdifference maps that were consistent with rotation of the bonds connecting pyrrole rings C and D. Further spectroscopic analyses showed that phycoviolobilin is susceptible to X-ray radiation damage, especially as Pg, during single-crystal X-ray diffraction analyses, which could complicate fine mapping of the various intermediate states. Fortunately, we found that PixJ crystals are amenable to serial femtosecond crystallography (SFX) analyses using X-ray free-electron lasers (XFELs). As proof of principle, we solved by room temperature SFX the GAF domain structure of Pb to 1.55-Å resolution, which was strongly congruent with synchrotron-based models. Analysis of these crystals by SFX should now enable structural characterization of the early events that drive phytochrome photoconversion.

Epitaxial Growth and Characterization of the Ordered Vacancy Compound CuIn3Se5 on GaAs (100) Fabricated by Molecular Beam Epitaxy

1994 ◽  
Vol 340 ◽  
Author(s):  
Art J. Nelson ◽  
M. Bode ◽  
G. Horner ◽  
K. Sinha ◽  
John Moreland
Keyword(s):  
Molecular Beam Epitaxy ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Structural Defects ◽  
X Ray Diffraction ◽  
Symmetric Vibration ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

ABSTRACTEpitaxial growth of the ordered vacancy compound (OVC) CuIn3Se5 has been achieved on GaAs (100) by molecular beam epitaxy (MBE) from Cu2Se and In2Se3 sources. Electron probe microanalysis and X-ray diffraction have confirmed the composition for the 1-3-5 OVC phase and that the film is single crystal Culn3Se5 (100). Transmission electron microscopy (TEM) characterization of the material also showed it to be single crystalline. Structural defects in the layer consisted mainly of stacking faults. Photoluminescence (PL) measurements performed at 7.5 K indicate that the bandgap is 1.28 eV. Raman spectra reveal a strong polarized peak at 152 cm−1, which is believed to arise from the totally symmetric vibration of the Se atoms in the lattice. Atomic force microscopy reveals faceting in a preferred (100) orientation.

Synthesis and Characterization of Low Density Bi-2223 Cuprates Superconductor Doped Eu2O3 Nanoparticles

2021 ◽  
Vol 317 ◽  
pp. 131-137
Author(s):  
Suhaimi Nurbaisyatul Ermiza ◽  
Azhan Hashim ◽  
Azman Kasim ◽  
Norazila Ibrahim ◽  
Siti Fatimah Saipuddin
Keyword(s):  
Solid State Reaction Method ◽  
Synthesis And Characterization ◽  
Crystallographic Structure ◽  
Low Density ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Resistivity Measurements

Bi1.6Pb0.4Sr2Ca2-xEuxCu3Oδ cuprates superconductor doped with Eu nanoparticles (x = 0.0000, 0.0025, 0.0200 and 0.0500) were synthesized through conventional solid state reaction method. Crystalline sucrose was added during pelletization and burn at 400°C for two hours to create low density sample. The effect of doping Eu2O3 nanoparticles on the structural and superconducting properties by means of critical temperature (Tc), critical current density (Jc), X-ray diffraction (XRD) together with Field Emission Scanning Electron Microscopy (FESEM) and Alternating Current Susceptibility (ACS) were studied. Based on XRD analyses, the crystallographic structure has shown slightly changed from tetragonal to orthorhombic. The amount of 2223 phase gradually decreased with the increment of Eu concentration which indicates that Eu nanoparticles substitution favours the growth of 2212 phases. The resistivity measurements show that the highest Tcvalue for doped samples found at 90 K for x = 0.0025. The FESEM images showed that the plate-like grains become smaller and distributed randomly without specific alignment due to the increment of Eu concentration.

PREPARATION AND CHARACTERIZATION OF CIS POWDERS BY A FACILE REFLUXING REACTION ROUTE

2013 ◽  
Vol 12 (05) ◽  
pp. 1350031
Author(s):  
J. C. ZHOU ◽  
Y. Y. WANG ◽  
X. L. GONG ◽  
S. W. LI
Keyword(s):  
Single Phase ◽  
Stoichiometric Composition ◽  
Chalcopyrite Structure ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Structure Morphology ◽  
Short Time

CuInSe 2 (CIS)-based powders were successfully prepared by a facile refluxing reaction route using metal halides and Se / S powder as raw starting materials. The phase and crystallographic structure, morphology, chemical composition of the products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS). It is found that single phase CIS powders with chalcopyrite structure can be prepared in a relatively short time using triethylenetetramine as the solvent; the most suitable reaction temperature and time are 200°C, 1–2 h, respectively. CuIn ( S x Se 1-x)2 powders were also prepared by refluxing reaction route using the mixed solvent of triethylenetetramine–glycol (1:1, v/v). The characterizations showed that the CuIn ( S x Se 1-x)2 has single chalcopyrite phase, and the stoichiometric composition closely follows the primary mixed ratio. The morphology of CuIn ( S x Se 1-x)2 is close to spheres, and the particle sizes become distinctly smaller with the incorporation of S . A possible formation mechanism of CuInSe 2 was put forward and briefly discussed.

Optical and X-Ray Diffraction Characterization of MBE-Grown InGaAs, InAlAs and InGaAIAs on InP

1994 ◽  
Vol 340 ◽  
Author(s):  
Z. C. Feng ◽  
S. J. Chua ◽  
A. Raman ◽  
N.N. Lim
Keyword(s):  
Optical Properties ◽  
Fourier Transform ◽  
Molecular Beam ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
X Ray ◽  
Lattice Matched ◽  
Comprehensive Characterization

ABSTRACTA variety of Inl-xGaxAs, Inl-yAlyAs and Inl-x-yGaxAlyAs films have been grown on InP by molecular beam epitaxy. A comprehensive characterization was performed using Raman scattering, photoluminescence (PL), Fourier transform infrared (FTIR) spectroscopy and double crystal X-ray diffraction on these ternary and quaternary heterostructures with different compositions and growth conditions. The lattice matched and mismatched structures are studied. Our analyses show that the interface mismatch exerts an important influence on the optical properties of these heterostructures, and conversely that Raman, PL and FTIR can be used to probe the interface mismatch nondestructively.

Characterization of molecular beam epitaxy grown CdF2 layers by x‐ray diffraction and CaF2:Sm photoluminescence probe

1995 ◽  
Vol 13 (6) ◽  
pp. 2703-2708 ◽  
Author(s):  
N. S. Sokolov ◽  
N. N. Faleev ◽  
S. V. Gastev ◽  
N. L. Yakovlev ◽  
A. Izumi ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
X Ray

Fabrication and characterization of ZnMgO nanowalls grown on 4H-SiC by molecular beam epitaxy

2019 ◽  
Vol 52 (1) ◽  
pp. 168-170
Author(s):  
Mieczyslaw A. Pietrzyk ◽  
Aleksandra Wierzbicka ◽  
Marcin Stachowicz ◽  
Dawid Jarosz ◽  
Adrian Kozanecki
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Optoelectronic Devices ◽  
Growth Conditions ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fabrication And Characterization

Control of nanostructure growth is a prerequisite for the development of electronic and optoelectronic devices. This paper reports the growth conditions and structural properties of ZnMgO nanowalls grown on the Si face of 4H-SiC substrates by molecular beam epitaxy without catalysts and buffer layers. Images from scanning electron microscopy revealed that the ZnMgO nanowalls are arranged in parallel rows following the stripe morphology of the SiC surface, and their thickness is around 15 nm. The crystal quality of the structures was evaluated by X-ray diffraction measurements.

High-Resolution X-Ray Characterization of Amorphous Semiconductor Multilayers

1989 ◽  
Vol 149 ◽  
Author(s):  
P. D. Persans ◽  
A. F. Ruppert ◽  
B. Abeles ◽  
G. Hughes ◽  
K. S. Liang
Keyword(s):  
Surface Roughness ◽  
High Resolution ◽  
Layer Thickness ◽  
Dynamical Theory ◽  
Amorphous Semiconductor ◽  
Structural Defects ◽  
X Ray Diffraction ◽  
X Ray

ABSTRACTWe discuss high-resolution x-ray diffraction measurements on a-Si:H/a-Ge:H periodic amorphous multilayers. Analysis of the data using the dynamical theory yields information on layer thicknesses and densities, interface and surface roughness, and structural defects such as layer thickness fluctuations.

Growth and Characterization of Pbse and Pbl-Sn1 Se Layers on Si (100)

1997 ◽  
Vol 487 ◽  
Author(s):  
H. K. Sachar ◽  
I. Chao ◽  
X. M. Fang ◽  
P. J. McCann
Keyword(s):  
Buffer Layer ◽  
Molecular Beam ◽  
Layer Structure ◽  
Good Growth ◽  
X Ray Diffraction ◽  
Growth Solution ◽  
X Ray ◽  
Layer Structures ◽  
Surface Morphologies

AbstractCrack-free layers of PbSe were grown on Si (100) by a combination of liquid phase epitaxy (LPE) and molecular beam epitaxy (MBE) techniques. The PbSe layer was grown by LPE on Si (100) using a MBE-grown PbSe/BaF2/CaF2 buffer layer structure. Pb1−xSnxSe layers with tin contents in the liquid growth solution equal to 3%, 5%, 6%, 7%, and 10%, respectively, were also grown by LPE on Si (100) substrates using similar buffer layer structures. The LPE-grown PbSe and Pb1−xSnxSe layers were characterized by optical Nomarski microscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Optical Nomarski characterization of the layers revealed their excellent surface morphologies and good growth solution wipe-offs. FTIR transmission experiments showed that the absorption edge of the Pb1−xSnxSe layers shifted to lower energies with increasing tin contents. The PbSe epilayers were also lifted-off from the Si substrate by dissolving the MBE-grown BaF2 buffer layer. SEM micrographs of the cleaved edges revealed that the lifted-off layers formed structures suitable for laser fabrication.

scholarly journals Growth and Characterization of M-Plane GaN Thin Films Grown on γ-LiAlO2 (100) Substrates

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Yu-Chiao Lin ◽  
Ikai Lo ◽  
Hui-Chun Shih ◽  
Mitch M. C. Chou ◽  
D. M. Schaadt
Keyword(s):  
Thin Films ◽  
High Resolution ◽  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Molecular Beam ◽  
Flux Ratio ◽  
Anisotropic Growth ◽  
X Ray Diffraction ◽  
X Ray

M-plane GaN thin films were grown on LiAlO2 substrates under different N/Ga flux ratios by plasma-assisted molecular beam epitaxy. An anisotropic growth of M-plane GaN was demonstrated against the N/Ga flux ratio. As the N/Ga flux ratio decreased by increasing Ga flux, the GaN surface trended to a flat morphology with stripes along [112-0]. According to high-resolution X-ray diffraction analysis, Li5GaO4 was observed on the interface between GaN and LiAlO2 substrate. The formation of Li5GaO4 would influence the surface morphology and crystal quality.

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