Structural Effects in Al(111)/Si(111) Heteroepitaxy by Partially Ionized Beam Deposition α

1988 ◽  
Vol 116 ◽  
pp. 465-470 ◽  
Author(s):  
A. S. Yapsir ◽  
C.-H. Choi ◽  
S. N. Yang ◽  
T.-M. Lu ◽  
M. Madden ◽  
...  
Keyword(s):  
Single Crystal ◽  
Lattice Mismatch ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Atom Ratio ◽  
Transmission Electron ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Partially Ionized ◽  
Acceleration Voltage

AbstractSingle crystal Al(111) films were grown on Si(111) surface at room temperature under a conventional vacuum condition using the partially ionized beam (PIB) deposition technique. The Al films were deposited with an ion to atom ratio of about 0.3% and an acceleration voltage of 1 kV. Transmission electron microscopy (TEM) analysis showed that the as-deposited films were single crystal with certain density of dislocation networks. These dislocations disappeared following a heat treatment at 450°C for 30 min. From X-ray diffraction and TEM patterns, it was observed that the Al(111) was aligned to the substrate with Al<1l0>//Si<1l0>. Possible mechanisms of the PIB epitaxial growth and a novel structural defect that is unique to this large lattice mismatch system are discussed.

Heteroepitaxial growth and structural analysis of epitaxial α–Fe2O3(1010) on TiO2(001)

2005 ◽  
Vol 20 (5) ◽  
pp. 1250-1256 ◽  
Author(s):  
Joshua R. Williams ◽  
Chongmin Wang ◽  
Scott A. Chambers
Keyword(s):  
Lattice Mismatch ◽  
High Energy ◽  
Unit Cell ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pole Figures ◽  
Large Lattice ◽  
Large Lattice Mismatch

We grew epitaxial α–Fe2O3(1010) on TiO2(001) rutile by oxygen plasma-assisted molecular-beam epitaxy. High-resolution transmission electron microscopy (HRTEM), reflection high-energy electron diffraction (RHEED), and x-ray diffraction pole figures confirm that the film is composed of four different in-plane orientations rotated by 90° relative to one another. For a given Fe2O3 unit cell, the lattice mismatch along the parallel [0001]Fe2O3 and [100]TiO2 directions is nominally +67%. However, due to a 3-fold repetition of the slightly distorted square symmetry of anion positions within the Fe2O3 unit cell, there is a coincidental anion alignment along the [0001]Fe2O3 and [100]TiO2 directions, which results in an effective lattice mismatch of only −0.02% along this direction. The lattice mismatch is nearly 10% in the orthogonal [1120]Fe2O3 and [100]TiO2 directions. The film is highly ordered and well registered to the substrate despite a large lattice mismatch in one direction. The film grows in registry with the substrate along the parallel [0001]Fe2O3 and [100]TiO2 directions and nucleates dislocations along the orthogonal [1120]Fe2O3 [100]TiO2 directions.

An X-ray scattering study on inverted Ge–Si huts grown at low temperatures

2004 ◽  
Vol 19 (4) ◽  
pp. 347-351
Author(s):  
J. Xu ◽  
X. S. Wu ◽  
B. Qian ◽  
J. F. Feng ◽  
S. S. Jiang ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Lattice Strain ◽  
Lattice Mismatch ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Large Lattice ◽  
Scattering Study

Ge–Si inverted huts, which formed at the Si∕Ge interface of Si∕Ge superlattice grown at low temperatures, have been measured by X-ray diffraction, grazing incidence X-ray specular and off-specular reflectivities, and transmission electron microscopy (TEM). The surface of the Si∕Ge superlattice is smooth, and there are no Ge–Si huts appearing on the surface. The roughness of the surfaces is less than 3 Å. Large lattice strain induced by lattice mismatch between Si and Ge is found to be relaxed because of the intermixing of Ge and Si at the Si∕Ge interface.

Properties of the magnetoresistive La0.8Sr0.2MnO3 film and integration with PbZr0.52 Ti0.48O3 ferroelectrics

2000 ◽  
Vol 617 ◽  
Author(s):  
Fumiaki Mitsugi ◽  
Tomoaki Ikegami ◽  
Kenji Ebihara ◽  
J. Narayan ◽  
A. M. Grishin
Keyword(s):  
Lattice Mismatch ◽  
Laser Energy ◽  
Single Crystal Substrate ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Colossal Magnetoresistive ◽  
Lsmo Film ◽  
Large Lattice ◽  
Crystal Substrate ◽  
Large Lattice Mismatch

AbstractThe colossal magnetoresistive La0.8Sr0.2MnO3 (LSMO) thin film was prepared on the MgO (100) single crystal substrate using KrF excimer pulsed laser deposition technique. The LSMO film deposited at the substrate temperature of 850 °C, oxygen pressure of 500 mTorr and laser energy density of 2 J/cm2(5 Hz) showed the resistivity peak temperature (Tp) of 330 K and the magnetoresi stance change of 15 %(H=0.7 T) at the room temperature. The large lattice mismatch with the substrate increased Tp and decreased the resistivity of the LSMO film.The X-ray diffraction measurement for the PbZr0.52Ti0.48O3 (PZT) / LSMO heterostructures indicated both c-axis and in- plane orientation, with the good PZT surface morphology.

Preparation and Characterization of CdSxTe1−x Alloys and Films

2001 ◽  
Vol 668 ◽  
Author(s):  
R.G. Dhere ◽  
D.S. Albin ◽  
S.E. Asher ◽  
H.R. Moutinho ◽  
D. Compton ◽  
...  
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Alloy Films ◽  
Present Generation ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Post Deposition

ABSTRACTIntermixing at the CdS/CdTe interface is considered crucial for the performance of CdTe-based solar cells. High-efficiency devices have been fabricated in spite of large lattice mismatch between CdS and CdTe. Intermixing and formation of CdSxTe1−x alloys in present-generation devices result from high-temperature CdTe deposition and post-deposition CdCl2 treatment. In this paper, we present our work on preparation of CdSxTe1−x-alloy powders and films. In this process, the CdS and CdTe powders are sized and mixed, isostatically pressed into a bar, sealed into closed-quartz ampoules, annealed at temperatures >1000°C, and water quenched. X-ray diffraction (XRD) analysis showed that they contained only distinct phases on S-rich and Te-rich sides of the phase diagram. Recently, two new batches of CdSxTe1−x material, produced by an improved process have been obtained (x =0.71 and x= 0.35 in CdSxTe1−x alloy). Initial XRD results from the films deposited by close spaced sublimation (CSS) using these powders reveal that both samples of bulk powders (prior to CSS deposition) are single-phase and demonstrate CdS-like characteristics (hexagonal). We have deposited CdSxTe1−x-alloy films using these powders. These alloy powders evaporate more congruently as opposed to mixed powders of CdS and CdTe. We will also present results on the structural properties of thin CdSxTe1−x alloy films deposited using these powders by CSS.

DC Magnetron Sputtering of B2 Phase Feal(111) Single-Crystal-Like Films and Hydrogen Damage Behavior

2013 ◽  
Vol 853 ◽  
pp. 131-134
Author(s):  
Tao Tang ◽  
Yi Liu ◽  
Qun Li ◽  
Jiang Li Cao ◽  
Yu Zhe Liu ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Tem Analysis ◽  
X Ray ◽  
Hydrogen Damage ◽  
Atomic Force ◽  
Transmission Electron ◽  
B2 Phase

B2 ordered FeAl intermetallic is an important candidate for high-temperaturestructural materials, and its hydrogen embrittlement problem has attracted wide attentions in recent decades. In this paper, we prepared single-crystal-like B2-FeAl (111) thin films on Si (111) substrate using the conventional magnetron sputtering method, and studied the phase composition and the influences of hydrogen on FeAl (111) films by X-ray diffraction (XRD), scanning electron microscopy (SEM), Atomic force microscope (AFM) and transmission electron microscope (TEM) analysis. The preffered growth mechanism of FeAl (111) film and its hydrogen induced modification were discussed.

scholarly journals Self-Assembled BaTiO3-MnZnFe2O4Nanocomposite Films

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Guo Yu ◽  
Feiming Bai ◽  
Huaiwu Zhang
Keyword(s):  
Remanent Polarization ◽  
Lattice Mismatch ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Mnzn Ferrite ◽  
Large Lattice ◽  
Out Of Plane ◽  
Large Lattice Mismatch ◽  
Plane Direction ◽  
Self Assembled

Self-assembled nanocomposite BaTiO3-Mn0.4Zn0.87Fe2O4magnetodielectric films have been grown on (001)-oriented SrTiO3substrates by a pulsed laser deposition method. High resolution X-ray diffraction shows that both BaTiO3and MnZn-ferrite phases are epitaxial along the out-of-plane direction with a 0–3 composite structure in spite of very large lattice mismatch. The magnetic, ferroelectric, and dielectric properties of the nanocomposite films are reported. A saturated magnetization of 330 emu/cc and double remanent polarization of 40 μC/cm2were obtained. Structural and compositional factors limiting the effective permeability and the dielectric constant will be discussed.

Undoped GaSb Growth by MOCVD

1990 ◽  
Vol 216 ◽  
Author(s):  
Yan Kuin Su ◽  
Fuh Shyang Juang
Keyword(s):  
Lattice Mismatch ◽  
Hole Concentration ◽  
Photoluminescence Intensity ◽  
Tem Analysis ◽  
Gaas Substrates ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Strain Layer Superlattice ◽  
Highly Strained ◽  
Epilayer Surface

ABSTRACTUndoped GaSb epilayers have been grown on (100) GaSb and S.I. GaAs substrates. The effects of growth temperatures and TMSb/TEGa mole fraction ratios on the epitaxial properties of surface morphology, growth rate, hole concentration and mobility (300K and 77K) have been studied. The lowest concentration 1.8x101 6 cm- 3 (77K) and the highest mdobility 1447 cm2/V.s (77K) can be obtained under V/III ratio of 6.64 at 550°C. Photoluminescence intensity was found to be a function of the V/III ratios. When V/III ratios increased or decreased beyond 6-8, the BE peaks disappeared and PL spectra became roughened.To reduce the effects of large lattice-mismatch in highly strained GaSb/GaAs system (7% mismatch) on the electrical properties, a 10-period In0.3Ga0.7As/GaAs (60A/40A) strain layer superlattice (SLS) has been grown on GaAs substrates as a dislocation filter before the GaSb epitaxial growth. From the comparison of 77K Hall mobility of GaSb/GaAs as a function of growth temperature with that of GaSb/SLS/GaAs, it was clearly observed that the epilayers grown on SLS structures have higher mobility than those grown directly on GaAs substrates. From the TEM analysis, we observed that all dislocations propagated up to the GaSb epilayer surface in the GaSb/GaAs system but some of the dislocations bending before reaching the epilayer surface in the GaSb/SLS/GaAs system.

Characterization of Interfacial Structure in Large Lattice Mismatch Heteroepitaxy: Ag/Si (111)

1990 ◽  
Vol 209 ◽  
Author(s):  
D.C. McKenna ◽  
G.-C. Wang ◽  
K. Rajan
Keyword(s):  
Lattice Mismatch ◽  
Interfacial Structure ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Interfacial Structures ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Diffraction Patterns

ABSTRACTThe interfacial structure of a large lattice mismatched (˜25%) (111) Ag-Si system was studied by using transmission electron diffraction (SADP - Selected Area Diffraction Pattern). The epitaxial films of Ag (600–1200Å) were grown by MBE on flat Si(111) and misoriented Si(1ll) surfaces. We have examined the interfacial structures of the Ag on 2° misoriented Si(111) using diffraction patterns of cross sectional view. Through a detail analysis of thelocation and shape of the diffraction spots, we can determine the epitaxial relationship between Ag and Si, the small tilt angle of Ag(111) planes withrespect to the misoriented Si(111), the period of the finite terrace size of the misoriented Si substrate, and the size of the ordered region in the Ag film. The O-lattice analysis developed by Bollmann has beenapplied to this interface andthe result is compared with the SADP observation.

Transmission electron microscopy observation and optical property of sol-gel derived LiNbO3 films

1996 ◽  
Vol 11 (12) ◽  
pp. 3152-3157 ◽  
Author(s):  
K. Terabe ◽  
A. Gruverman ◽  
Y. Matsui ◽  
N. Iyi ◽  
K. Kitamura
Keyword(s):  
Lattice Mismatch ◽  
Sol Gel ◽  
Misfit Dislocations ◽  
Microscopy Observation ◽  
Continuous Film ◽  
Transmission Electron ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Interface Structures ◽  
Optical Waveguiding

Crystallization behavior, defects, and interface structures of sol-gel derived LiNbO3 films on three kinds of substrates were examined. The nucleation was found to occur epitaxially at the interface between the film and the substrate. The continuous film is formed by coalescence of the island-like crystallites. When sapphire substrate is used, which has large lattice mismatch with the LiNbO3, the resulting film contains a large amount of micropores, twin structures, and misfit dislocations. On the other hand, while LiTaO3 and 5% MgO-doped LiNbO3 substrates with smaller mismatch are used as substrates, the films show no evidence of the formation of dislocations and twins. The film on 5% MgO-doped LiNbO3 substrate shows better optical waveguiding property.

Characteristics of titanium oxide films deposited by an activated reactive evaporation method

1994 ◽  
Vol 9 (6) ◽  
pp. 1468-1473 ◽  
Author(s):  
Tatsuo Fujii ◽  
Naoki Sakata ◽  
Jun Takada ◽  
Yoshinari Miura ◽  
Yoshihiro Daitoh ◽  
...  
Keyword(s):  
Titanium Oxide ◽  
Lattice Mismatch ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
Rutile Structure ◽  
Evaporation Method ◽  
Reactive Evaporation ◽  
Transmission Electron ◽  
Large Lattice Mismatch ◽  
Activated Reactive Evaporation

Titanium di- and sesquioxide films were epitaxially grown on the (001) surface of sapphire single-crystalline substrates by an activated reactive evaporation method. Formation range for each titanium oxide was determined as a function of oxygen pressure (Po2) by means of x-ray diffraction, transmission electron microscopy, and Raman spectroscopy. Films prepared at Po2 ≥ 2.0 × 10−4 Torr were stoichiometric (100)-oriented rutile of TiO2, and with decreasing Po2 they would accommodate more and more Ti3+ ions in the rutile structure. At Po2 = 0.6 × 10−4 Torr, on the other hand, (001)-oriented Ti2O3 was formed and an electrical transition was clearly detected at about 400 K. However, the large lattice mismatch between the substrate and these films leads to a periodic introduction of misfit dislocations in the case of the TiO2 films and a mixing of stacking sequences for the Ti2O3 films.

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