Strained Field of Silver Overlayers Deposited on the Reconstructed Si(111) Surface

1992 ◽  
Vol 280 ◽  
Author(s):  
L. J. Martinez-Miranda ◽  
J. J. Santiago-Aviles ◽  
Raul Perez-Sandoz ◽  
Randolph Carolissen ◽  
H. H. Weitering ◽  
...  
Keyword(s):  
Plane Strain ◽  
Strain Field ◽  
Present System ◽  
Unexpected Result ◽  
X Ray Diffraction ◽  
Lattice Match ◽  
Rocking Curve ◽  
Out Of Plane ◽  
Unit Cells ◽  
Plane Diffraction

ABSTRACTWe have performed high resolution x-ray diffraction measurements of the strain field in UHV deposited Ag(111) films on a 7×7 reconstructed Si(111) surfaces shows a faulted epitaxial layer with a 0.4% out-of-plane strain, and a -1% in-plane strain. The strain field anisotropy is similar to that observed on epitaxial YSi2-x on Si(111), and is an unexpected result for the present system, due to the lack of a lattice match between the silver and silicon unit cells. The out-of-plane diffraction peaks have an angular distribution of 1.23°, full width at half maximum (FWHM), as determined from rocking curve measurements.

Dielectric and Electromechanical Behaviour of Relaxor [(1−x)Pb(Mg1/3Nb2/3)O3 -xPbTiO3] Thin Films

2001 ◽  
Vol 688 ◽  
Author(s):  
N.J. Donnelly ◽  
G. Catalan ◽  
C. Morros ◽  
R.M. Bowman ◽  
J.M. Gregg
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Plane Strain ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Bulk Ceramic ◽  
Atomic Force ◽  
Out Of Plane ◽  
Order Of Magnitude

AbstractThin film capacitor structures of Au / (1−x)Pb(Mg1/3Nb2/3)O3 - xPbTiO3 /(La1/2Sr1/2)CoO3 were fabricated by pulsed laser deposition on single crystal {001} MgO substrates. Films were found to be perovskite dominated and highly {001} oriented. Dielectrically, films displayed relaxorlike features, though maximum permittivity was low compared to single crystal or bulk ceramic (∼1400 at peak @1kHz, for x=0.07, 0.1 & 0.2). A field induced piezoelectric coefficient d33 was measured by piezoresponse atomic force microscopy for specific compositions x =0, × =0.07, and x =0.1 and found to be disappointingly low - indicating poor electric field induced strain. Despite this macroscopic electrostrictive coefficients Q33 were found to be (3.6 ± 0.6) ×10−2C−2m4, (2.6 ± 0.2) ×10−2C−2m4, and (0.9 ± 0.3) ×10−2C−2m4 respectively. Crystallographic electrostrictive coefficients were determined by in-situ x-ray diffraction and found to be (4.9 ± 0.2) ×10−2C−2m4 for PMN-(0.07)PT and (1.9 ± 0.1) ×10−2C−2m4 for PMN-(0.1)PT. Considering that all these Q33 values are of the same order of magnitude as found in single crystal experiments (2.5 – 3.8 ×10−2C−2m4), it is suggested that low out-of-plane strain is entirely a result of reduced polarisability rather than reduced electrostrictive coefficients in thin films relative to bulk ceramic or single crystal. An estimate was also made of the Q13 electrostrictive coefficient for PMN and PMN-(0.07)PT by measuring permittivity as a function of applied in-plane strain. The values obtained were -1.31 ×10−2C−2m4 and -0.46 ×10−2C−2m4 respectively.

X-ray Topography of Strain Fields Induced by 100 MeV Ti7+ Ion Irradiated Si(100)

1995 ◽  
Vol 378 ◽  
Author(s):  
B. B. Sharma ◽  
S. R. Gupta ◽  
R. K. Sharma ◽  
V. Kumar ◽  
U. Tiwari ◽  
...  
Keyword(s):  
Plane Strain ◽  
Strain Field ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Lattice Deformation ◽  
Beam Direction ◽  
Strain Fields ◽  
X Ray ◽  
Projected Range ◽  
Out Of Plane

AbstractThe lattice deformation caused by 100 MeV Ti7+ ion irradiation in Si (100) has been studied using X-ray topographic techniques. An important finding is the appearance of a strain field perpendicular to the ion beam direction in the irradiated region well separated from the projected range of implanted ions. This in-plane strain extends in the bulk of the sample and is not merely confined to the surface. The implanted region has been found to experience an out of plane strain which is expected to be tensile in nature.

White-Beam Transmission Characterization of Texture in Mo Thin Films and Mo/W Multilayers

1993 ◽  
Vol 317 ◽  
Author(s):  
Marc Vill ◽  
S. G. MALHOTRA ◽  
Z. Rek ◽  
S. M. Yalisove ◽  
J. C. Bilello
Keyword(s):  
Growth Direction ◽  
X Rays ◽  
X Ray Diffraction ◽  
Orientation Data ◽  
X Ray ◽  
White Beam ◽  
Out Of Plane ◽  
Transmission Study ◽  
Beam Transmission ◽  
Plane Diffraction

ABSTRACTSynchrotron white-beam (polychromatic) x-ray radiation was used in a transmission Laue study of texture in monolithic mo films and Mo/W Multilayers. High intensity synchrotron radiation permits x-ray diffraction study of mo specimens >100μm in thickness, while 6μm is the practical thickness limit for a transmission study using a rotating anode x-ray source. The transmission Laue technique permits the collection of preferred orientation data from several families of diffracting planes on one photographic exposure. Polychromatic x-rays facilitate collection of diffraction information from a range of planar orientations without altering the orientation of the sample with respect to the incident x-ray beam. The texture information from a 35μm thick monolithic mo film and a 31μm thick multilayer of mo and W is presented. Two-fold symmetry seen in the {211} plane diffraction ring of the multilayer demonstrated both an in-plane and out-of-plane texture with a <110> growth direction. Three fold symmetry seen in the {310} and {222} plane diffraction rings of the monolithic mo film demonstrated both in-plane and out-of-plane texture which suggests a <111> growth direction.

{224} Plane X-Ray Diffraction Study of GaAs on Si Wafers Using a Conventional Double Crystal Diffractometer

1987 ◽  
Vol 91 ◽  
Author(s):  
J.W. Lee ◽  
D.K. Bowen ◽  
J.P. Salerno
Keyword(s):  
Incident Angle ◽  
Wafer Surface ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Near Surface ◽  
Rocking Curve ◽  
X Ray ◽  
Gaas On Si ◽  
Plane Diffraction

ABSTRACTIn an effort to evaluate the near surface crystal quality of GaAs on Si wafers, {224} plane diffraction were investigated using a conventional double crystal x-ray diffractometer without any high intensity radiation source. The x-ray incident angle to wafer surface varied from 3.6 to 9.6 degrees for different {224} planes due to the substrate tilt angle of 3 degrees. The GaAs to Si rocking curve intensity ratio increased significantly as the incident angle decreased. For the diffraction with 3.6 degree incident angle, only the GaAs peak was detected from the 3.5 um thick GaAs on Si wafer and the GaAs peak became narrower. These indicates that this conventional x-ray diffraction technique is applicable for the near surface quality evaluation of GaAs on Si wafers.

An Investigation of the Structural Strains and the Breakdown of Poisson'S Effect in Lattice-Mismatched BCC(110)/FCC(111) Metallic Superlattices

1992 ◽  
Vol 280 ◽  
Author(s):  
A. Fartash ◽  
Ivan K. Schuller ◽  
M. Grimsditch
Keyword(s):  
Structural Feature ◽  
Elasticity Theory ◽  
Plane Strain ◽  
Lattice Spacing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Out Of Plane ◽  
Anisotropic Lattice

ABSTRACTThe strain profiles of individual layers of a selected group of stable bcc(110)/fcc(111) metallic superlattices which have been determined by x-ray diffraction methods are compared, and discussed in terms of a number of mechanisms proposed for explaining their anomalous properties. The superlattices in this group are distinguished in terms of a highly anisotropic lattice spacing mismatch of their adjoining bcc and fcc layers (∼20% vs. 3%). The most prominent structural feature of the bcc layers consists of a highly anisotropic in-plane contraction accompanied with a small out-of-plane strain. The fee layers are found to show large out-of-plane expansions which based on their small in-plane expansions cannot be explained within framework of standard elasticity theory.

scholarly journals 3D Strain Field Evolution and Failure Mechanisms in Anisotropic Paperboard

2021 ◽  
Author(s):  
S. Johansson ◽  
J. Engqvist ◽  
J. Tryding ◽  
S. A. Hall
Keyword(s):  
Plane Strain ◽  
Strain Field ◽  
Failure Mechanisms ◽  
Strain Tensor ◽  
Peak Load ◽  
Sample Thickness ◽  
Deformation And Failure ◽  
Field Patterns ◽  
Field Evolution ◽  
Out Of Plane

Abstract Background Experimental analyses of the 3D strain field evolution during loading allows for better understanding of deformation and failure mechanisms at the meso- and microscale in different materials. In order to understand the auxetic behaviour and delamination process in paperboard materials during tensile deformation, it is essential to study the out-of-plane component of the strain tensor that is, in contrast to previous 2D studies, only achievable in 3D. Objective The main objective of this study is to obtain a better understanding of the influence of different out-of-plane structures and in-plane material directions on the deformation and failure mechanisms at the meso- and microscale in paperboard samples. Methods X-ray tomography imaging during in-situ uniaxial tensile testing and Digital Volume Correlation analysis was performed to investigate the 3D strain field evolution and microscale mechanical behaviour in two different types of commercial paperboards and in two material directions. The evolution of sample properties such as the spatial variation in sample thickness, solid fraction and fibre orientation distribution were also obtained from the images. A comprehensive analysis of the full strain tensor in paperboards is lacking in previous research, and the influence of material directions and out-of-plane structures on 3D strain field patterns as well as the spatial and temporal quantification of the auxetic behaviour in paperboard are novel contributions. Results The results show that volumetric and deviatoric strain, dominated by the out-of-plane normal strain component of the strain tensor, localize in the out-of-plane centre already in the initial linear stress-strain regime. In-plane strain field patterns differ between samples loaded in the Machine Direction (MD) and Cross Direction (CD); in MD, strain localizes in a more well-defined zone close to the notches and the failure occurs abruptly at peak load, resulting in angular fracture paths extending through the stiffer surface planes of the samples. In CD, strain localizes in more horizontal and continuous bands between the notches and at peak load, fractures are not clearly visible at the surfaces of CD-tested samples that appear to fail internally through more well-distributed delamination. Conclusions In-plane strain localization preceded a local increase of sample thickness, i.e. the initiation of the delamination process, and at peak load, a dramatic increase in average sample thickening occurred. Different in-plane material directions affected the angles and continuity of the in-plane strain patterns as well as the sample and fracture properties at failure, while the out-of-plane structure affected how the strain fields distributed within the samples.

Texture of NiGe(Sn) on Ge(100) and its evolution with Sn content

2021 ◽  
Vol 54 (5) ◽  
pp. 1306-1316
Author(s):  
Andrea Quintero ◽  
Patrice Gergaud ◽  
Tra Nguyen-Thanh ◽  
Jean-Michel Hartmann ◽  
Vincent Reboud ◽  
...  
Keyword(s):  
The Other ◽  
X Ray Diffraction ◽  
Rich Phase ◽  
X Ray ◽  
Pole Figures ◽  
Out Of Plane ◽  
Diffraction Peaks ◽  
The Impact ◽  
Plane Diffraction

The texture of the Ni monostanogermanide phase on a Ge(100) substrate was evaluated during a solid-state reaction, with a focus on the impact of Sn addition. Complementary X-ray diffraction analyses involving in situ X-ray diffraction, in-plane reciprocal space maps (RSMs) and pole figures were used to that end. A sequential growth of the phases for the Ni/Ge(Sn) system was found. An Ni-rich phase formed first, followed by the NiGe(Sn) phase. The NiGe and NiGe(Sn) layers were polycrystalline with different out-of-plane orientations. The number of out-of-plane diffraction peaks decreased with the Sn content, while the preferred orientation changed. In-plane RSM analyses confirmed these results. Sn addition modified the out-of-plane and in-plane orientations. Pole figure analysis revealed that numerous epitaxial texture components were present for the Ni/Ge system, while Sn addition reduced the number of epitaxial texture components. On the other hand, segregated Sn crystallized with an epitaxial alignment with the Ge substrate underneath.

X-ray diffraction properties of curved crystal diffractors

1992 ◽  
Vol 50 (2) ◽  
pp. 1734-1735
Author(s):  
W. Z. Chang ◽  
D. B. Wittry
Keyword(s):  
Diffraction Theory ◽  
X Rays ◽  
Diffraction Image ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Bent Crystal ◽  
Diffraction Geometry ◽  
Crystal Parameter ◽  
Quantitative Procedure

Since Du Mond and Kirkpatrick first discussed the principle of a bent crystal spectrograph in 1930, curved single crystals have been widely utilized as spectrometric monochromators as well as diffractors for focusing x rays diverging from a point. Curved crystal diffraction theory predicts that the diffraction parameters - the rocking curve width w, and the peak reflection coefficient r of curved crystals will certainly deviate from those of their flat form. Due to a lack of curved crystal parameter data in current literature and the need for optimizing the choice of diffraction geometry and crystal materials for various applications, we have continued the investigation of our technique presented at the last conference. In the present abstract, we describe a more rigorous and quantitative procedure for measuring the parameters of curved crystals.The diffraction image of a singly bent crystal under study can be obtained by using the Johann geometry with an x-ray point source.

Chemical and Electrochemical Heteroepitaxial Growth of Chalcogenide Semiconductors from Solutions

1996 ◽  
Vol 451 ◽  
Author(s):  
D. Lincot ◽  
M. J. Furlong ◽  
M. Froment ◽  
R. Cortes ◽  
M. C. Bernard
Keyword(s):  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Basic Principles ◽  
Lattice Match ◽  
X Ray ◽  
Chalcogenide Semiconductors ◽  
Influence Of Temperature On ◽  
Deposition Processes ◽  
A Site ◽  
Site Selective

ABSTRACTChalcogenide semiconductors have been deposited epitaxially from aqueous solutions either chemically or electrochemically at growth rates of up to 0.7 μmhr−1. After recalling the basic principles of these deposition processes, results are presented concerning chemically deposited CdS on InP, GaP and CuInSe2 substrates, electrodeposited CdTe on InP, and CdSAnP heterostructures. Characterisation of these structures by RHEED, TEM, HRTEM, and glazing angle X ray diffraction allows to analyse the effects of substrate orientation, polarity, lattice match plus the influence of temperature on epitaxial growth. These results are discussed in terms of self organisation and a site selective growth mechanisms due to the free enegy of formation of each compound.

scholarly journals Effective Complex Properties for Three-Phase Elastic Fiber-Reinforced Composites with Different Unit Cells

Technologies ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 12
Author(s):  
Federico J. Sabina ◽  
Yoanh Espinosa-Almeyda ◽  
Raúl Guinovart-Díaz ◽  
Reinaldo Rodríguez-Ramos ◽  
Héctor Camacho-Montes
Keyword(s):  
Effective Properties ◽  
Elastic Fiber ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Effective Coefficients ◽  
Three Phase ◽  
Out Of Plane ◽  
Local Problems ◽  
Unit Cells

The development of micromechanical models to predict the effective properties of multiphase composites is important for the design and optimization of new materials, as well as to improve our understanding about the structure–properties relationship. In this work, the two-scale asymptotic homogenization method (AHM) is implemented to calculate the out-of-plane effective complex-value properties of periodic three-phase elastic fiber-reinforced composites (FRCs) with parallelogram unit cells. Matrix and inclusions materials have complex-valued properties. Closed analytical expressions for the local problems and the out-of-plane shear effective coefficients are given. The solution of the homogenized local problems is found using potential theory. Numerical results are reported and comparisons with data reported in the literature are shown. Good agreements are obtained. In addition, the effects of fiber volume fractions and spatial fiber distribution on the complex effective elastic properties are analyzed. An analysis of the shear effective properties enhancement is also studied for three-phase FRCs.

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