3C-SiC Monocrystals Grown on Undulant Si(001) Substrates

2002 ◽  
Vol 742 ◽  
Author(s):  
Hiroyuki Nagasawa ◽  
Kuniaki Yagi ◽  
Takamitsu Kawahara ◽  
Naoki Hatta
Keyword(s):  
Electrical Properties ◽  
Stacking Faults ◽  
X Ray Diffraction ◽  
Growth Step ◽  
Planar Defects ◽  
X Ray ◽  
Step Flow ◽  
Si Substrates ◽  
Novel Technique ◽  
Initial Stage

ABSTRACTA novel technique to reduce planar defects in 3C-SiC is to grow it on “undulant-Si” substrates, on which the surface forms countered slopes oriented in the [110] and [110] directions. In the initial stage of 3C-SiC growth, step flow epitaxy occurs on each slope of the substrate, reducing the anti-phase boundaries. Then, the stacking faults in the (111) and (111) planes are gradually annihilated by combining with counter-stacking faults, while those parallel to (111) and (111) vanish. The freestanding 3C-SiC exhibits anisotropy in its electrical properties. The origin of the anisotropy in electrical properties is discussed by referring to the results of X-ray diffraction study.

scholarly journals X-ray investigation of polytype distribution in InAs nanowires during MBE growth

2014 ◽  
Vol 70 (a1) ◽  
pp. C748-C748
Author(s):  
Ullrich Pietsch ◽  
Andreas Biermanns ◽  
Emmanouil Dimakis ◽  
Lutz Geelhaar ◽  
Anton Davydok ◽  
...  
Keyword(s):  
Time Evolution ◽  
Stacking Faults ◽  
Growth Conditions ◽  
Growth Mode ◽  
Ex Situ ◽  
Growth Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Liquid Indium

The monolithic integration of III-V semiconductors with Si is the ideal way to combine the superior optoelectronic properties of the compound semiconductors with the mature Si technology. This integration can be realized by growing epitaxially dislocation-free III-V NWs on Si substrates either in the vapor-liquid-solid (VLS) or in the vapor-solid (VS) mode associated with the presence or absence, respectively, of group-III liquid droplets on the NW tips [1]. In this work, we investigate the correlation between the growth mode and the forming polytypes in InAs NWs grown on Si(111). The growth was performed in the molecular beam epitaxy chamber of beamline 11XU at Spring8 [2], while the structural dynamics was probed by in situ x-ray diffraction. Specifically, the time evolution of the formation of wurtzite (WZ) and zincblende (ZB) polytypes was monitored during the NW growth. Despite the As-rich growth conditions, a spontaneous build-up of liquid In on Si was found to be present in the nucleation phase, where the InAs nuclei mainly grow in the WZ phase with low number of stacking faults. Shortly after the nucleation, the liquid In is consumed by the excessive As, and the growth continues in the VS mode with an increasing density of stacking faults forming in the NW crystal. The time evolution of the liquid Indium signal (Fig. (a)) correlates well with the time evolution of wurzite growth rate (Fig (b)). The latter saturates at a time where the liquid indium disappers, i.e. where the VLS changes into the VS mode, whereas the zinc-blende polytypes grow almost continuous in both VLS and VS growth mode. The dynamics of stacking faults density was determined quantitatively by ex-situ X-ray diffraction measuring thestacking fault induced increase of the peak width of wurtzite reflections at InAs nanowire samples of different length ; i.e. growth time [3].

Applications of Ultramicrotomy in the Electron Microscopy of Clay Minerals

1972 ◽  
Vol 30 ◽  
pp. 380-381
Author(s):  
John L. Brown
Keyword(s):  
Electron Microscopy ◽  
Clay Minerals ◽  
Stacking Faults ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
Lattice Image ◽  
Oriented Sample ◽  
Growth Step ◽  
Water Suspension ◽  
X Ray

Large flakes of a specimen muscovite from Amelia, Virginia were broken apart in water with an Omni-Mixer, and the fraction between 0.2 and 2μ was separated by centrifugation. An oriented sample of the fraction gave a sharp 10Å X-ray diffraction peak as well as integral higher orders of this (001) reflection. A portion of the same sample was deposited from water suspension onto the surface of an Araldite slab. Additional resin was added and cured to form a sandwich. Sections were cut perpendicular to the sediment plane and examined in a Philips Em-200 microscope at 100KV. Figure 1 shows a lattice image of the (001) planes with indications of stacking faults and growth-step planes. Another portion of the muscovite fraction was subjected to repeated treatments in an autoclave with 0.1N BaCl2 until 76% of the potassium was replaced by barium. The resultant sample gave a 12.1Å (001) X-ray reflection or 9.9Å if dried over P2O5.

Epitaxial Relationships and Electrical Properties of SrTiO3 Films on Various Thin -Fluoride/Si Structures

1994 ◽  
Vol 341 ◽  
Author(s):  
B. K. Moon ◽  
H. Ishiwara
Keyword(s):  
Buffer Layer ◽  
Buffer Layers ◽  
Breakdown Field ◽  
X Ray Diffraction ◽  
Dielectric Characteristics ◽  
X Ray ◽  
Si Substrates ◽  
Initial Stage ◽  
Growth Method ◽  
Step Growth

AbstractCrystalline strontium titanate (SrTiO3:STO) films were grown on Si(111) and Si(100) substrates using thin SrF2 and CaF2 buffer layers by two-step growth method. In all cases, fluoride buffer layers were effective in growing STO films on Si substrates, which is probably due to that fluoride buffer layers have excellent crystallinity and they can prevent formation of amorphous SiO2 layers on Si substrates at the initial stage of the STO deposition. It was found from X-ray diffraction and pole-figure measurements that (110)-oriented STO crystallites with three different positions to the substrate were grown on Si(111) substrates for both SrF2 and CaF2 buffer layers. In constrast, (100)-oriented STO films with 12-fold symmetry were grown on a SrF2/Si(100), and mixed (110)- and (100)-oriented STO crystallites were grown on a CaF2/Si(100) structure. It was concluded from these results that better crystallinity of STO films can be obtained on the SrF2 buffer layer in case of Si(111) and on the CaF2 buffer layer in case of Si(100). It was also found from I-V and C-V analyses that the STO films have good insulating and dielectric characteristics. For a SrTiO3 film on SrF2/Si(111) structure, the best values of breakdown field (at l.μA/cm2), resistivity (at IMV/cm) and dielectric constant were 2.3MV/cm, 8.2 × 1012 Ωcm and 72, respectively.

Microstructure and properties of PbZr0.6Ti0.4O3 and PbZrO3 thin films deposited on template layers

2000 ◽  
Vol 15 (9) ◽  
pp. 1962-1971 ◽  
Author(s):  
R. E. Koritala ◽  
M. T. Lanagan ◽  
N. Chen ◽  
G. R. Bai ◽  
Y. Huang ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Chemical Vapor ◽  
Dielectric Constants ◽  
Breakdown Field ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
Si Substrates ◽  
Antiferroelectric Phase

Polycrystalline Pb(ZrxTi1−x)O3 thin films with x = 0.6 and 1.0 were deposited at low temperatures (450–525 °C) on (111)Pt/Ti/SiO2/Si substrates by metalorganic chemical vapor deposition. The films were characterized by x-ray diffraction, electron microscopy, and electrical measurements. The texture of the films could be improved by using one of two template layers: PbTiO3 or TiO2. Electrical properties, including dielectric constants, loss tangents, polarization, coercive field, and breakdown field, were also examined. PbZrO3 films on Pt/Ti/SiO2/Si with a pseudocubic (110) orientation exhibited an electric-field-induced transformation from the antiferroelectric phase to the ferroelectric phase. The effect of varying processing conditions on the microstructure and electrical properties of the films is discussed.

Defect structures of Nb1+αS2 sulfidation scales

1992 ◽  
Vol 50 (1) ◽  
pp. 38-39
Author(s):  
Chuxin Zhou ◽  
L. W. Hobbs
Keyword(s):  
Stacking Faults ◽  
Rhombohedral Structure ◽  
Stacking Sequence ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plane Normal ◽  
Lower Case ◽  
Sulfur Layer ◽  
Two Phases

One of the major purposes in the present work is to study the high temperature sulfidation properties of Nb in severe sulfidizing environments. Kinetically, the sulfidation rate of Nb is satisfactorily slow, but the microstructures and non-stoichiometry of Nb1+αS2 challenge conventional oxidation/sulfidation theory and defect models of non-stoichiometric compounds. This challenge reflects our limited knowledge of the dependence of kinetics and atomic migration processes in solid state materials on their defect structures.Figure 1 shows a high resolution image of a platelet from the middle portion of the Nb1+αS2 scale. A thin lamellar heterogeneity (about 5nm) is observed. From X-ray diffraction results, we have shown that Nb1+αS2 scale is principally rhombohedral structure, but 2H-NbS2 can result locally due to stacking faults, because the only difference between these 2H and 3R phases is variation in the stacking sequence along the c axis. Following an ABC notation, we use capital letters A, B and C to represent the sulfur layer, and lower case letters a, b and c to refer to Nb layers. For example, the stacking sequence of 2H phase is AbACbCA, which is a ∼12Å period along the c axis; the stacking sequence of 3R phase is AbABcBCaCA to form an ∼18Å period along the c axis. Intergrowth of these two phases can take place at stacking faults or by a shear in the basal plane normal to the c axis.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Fabrication and study the effect of the laser on the properties of the compound Tl2-xHgxBa2-ySryCa2Cu3O10+δ superconductor

2018 ◽  
pp. 168
Author(s):  
A. Kareem Dahash Ali ◽  
Nihad Ali Shafeek
Keyword(s):  
Transition Temperature ◽  
Solid State ◽  
Hydrostatic Pressure ◽  
Electrical Properties ◽  
Co2 Laser ◽  
Temperature Shift ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Electrical Properties

This study included the fabrication of    compound (Tl2-xHgxBa2-ySryCa2Cu3O10+δ) in a manner solid state and under hydrostatic pressure ( 8 ton/cm2) and temperature annealing(850°C), and determine the effect of the laser on the structural and electrical properties elements in the compound, and various concentrations of x where (x= 0.1,0.2,0.3 ). Observed by testing the XRD The best ratio of compensation for x is 0.2 as the value of a = b = 5.3899 (A °), c = 36.21 (A °) show that the installation of four-wheel-based type and that the best temperature shift is TC= 142 K  .When you shine a CO2 laser on the models in order to recognize the effect of the laser on these models showed the study of X-ray diffraction of these samples when preparing models with different concentrations of the values ​​of x, the best ratio of compensation is 0.2 which showed an increase in the values ​​of the dimensions of the unit cell a=b = 5.3929 (A °), c = 36.238 (A°). And the best transition temperature after shedding laser is TC=144 K. 

scholarly journals Heterogeneity of the Dendrite Array Created in the Root of Cored SX Turbine Blades during Initial Stage of Crystallization

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 80
Author(s):  
Robert Paszkowski ◽  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz ◽  
Dariusz Szeliga ◽  
Jan Sieniawski
Keyword(s):  
Transverse Section ◽  
Turbine Blades ◽  
Lateral Growth ◽  
X Ray Diffraction ◽  
Dendrite Branching ◽  
X Ray ◽  
Initial Stage ◽  
Vertical Bridgman ◽  
Lateral Dendrite ◽  
Root Connection

The roots of cored single-crystalline turbine blades made of a nickel-based CMSX-4 superalloy were studied. The casts were solidified by the vertical Bridgman method in an industrial ALD furnace using the spiral selector and selector continuer situated asymmetrically in the blade root transverse section. Scanning electron microscopy, the Laue diffraction and X-ray diffraction topography were used to visualize the dendrite array and the local crystal misorientation of the roots. It has been stated that heterogeneity of the dendrite array and creation of low-angle boundaries (LABs) are mostly related to the lateral dendrite branching and rapid growth of the secondary and tertiary dendrites near the surface of the continuer–root connection. These processes have an unsteady character. Additionally, the influence of the mould walls on the dendrite array heterogeneity was studied. The processes of the lateral growth of the secondary dendrites and competitive longitudinal growth of the tertiary dendrites are discussed and a method of reducing the heterogeneity of the root dendrite array is proposed.

Initial stage of copper thermal oxidation studied by UV-vis-NIR reflectance spectroscopy, XPS and X-ray diffraction

1988 ◽  
Vol 23 (10) ◽  
pp. 1379-1388 ◽  
Author(s):  
J.M. Machefert ◽  
A. D'Huysser ◽  
M. Lenglet ◽  
J. Lopitaux ◽  
D. Delahaye
Keyword(s):  
Thermal Oxidation ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initial Stage ◽  
Nir Reflectance Spectroscopy

scholarly journals Local Strain Distribution in ZnO Microstructures Visualized with Scanning Nano X‐Ray Diffraction and Impact on Electrical Properties

2021 ◽  
pp. 2100201
Author(s):  
Philipp Jordt ◽  
Stjepan B. Hrkac ◽  
Jorit Gröttrup ◽  
Anton Davydok ◽  
Christina Krywka ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Strain Distribution ◽  
Local Strain ◽  
X Ray Diffraction ◽  
X Ray
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