Evaluation of the strain state in SiGe/Si heterostructures by high resolution X-ray diffraction and convergent beam electron diffraction

2005 ◽  
Author(s):  
S.L. Toh ◽  
K. Li ◽  
C.H. Ang ◽  
R. Rao ◽  
E. Er ◽  
...  
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Strain State ◽  
Convergent Beam Electron Diffraction ◽  
X Ray Diffraction ◽  
Beam Electron ◽  
X Ray ◽  
Convergent Beam

Measurement of Debye-Waller factors of silicon as a function of temperature using energy-filtered CBED rocking-curve technique

1994 ◽  
Vol 52 ◽  
pp. 996-997
Author(s):  
S. Swaminathan ◽  
S. Altynov ◽  
I. P. Jones ◽  
N. J. Zaluzec ◽  
D. M. Maher ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Liquid Nitrogen Temperature ◽  
Convergent Beam Electron Diffraction ◽  
Higher Order ◽  
X Ray Diffraction ◽  
Beam Electron ◽  
X Ray ◽  
Crystal Potential ◽  
Transmission Electron ◽  
Convergent Beam

The advantages of quantitative Convergent Beam Electron Diffraction (CBED) method for x-ray structure factor determination have been reviewed by Spence. The CBED method requires accurate values of Debye-Waller (D-W) factors for the estimation of the coefficients of crystal potential of the higher order beams, Vg, the calculation of the absorption potential, V′g using the Einstein model for phonons, and finally the conversion of the fitted values of the coefficients of crystal potential, V″, to x-ray structure factors. Debye-Waller factors are conventionally determined by neutron or x-ray diffraction methods. Because of the difficulties in conducting high temperature neutron and x-ray diffraction experiments, D-W factors are rarely measured at temperatures above room temperature. Debye-Waller factors at high temperatures can be determined by Convergent Beam Electron diffraction (CBED) method using Transmission Electron Microscopy (TEM) employed with a hot stage attachment. Recently Holmestad et al. have attempted to measure the D-W factors by matching the energy-filtered Higher Order Laue Zone (HOLZ) line intensities near liquid nitrogen temperature.

Relative Lattice Parameter Measurement in Quaternary (InGaAsP) Layers on InP Substrates Using Convergent Beam Electron Diffraction

1986 ◽  
Vol 69 ◽  
Author(s):  
M. E. Twigg ◽  
S. N. G. Chu ◽  
D. C. Joy ◽  
D. M. Maher ◽  
A. T. Macrander ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Lattice Parameter ◽  
Convergent Beam Electron Diffraction ◽  
X Ray Diffraction ◽  
Device Structure ◽  
Beam Electron ◽  
X Ray ◽  
Convergent Beam ◽  
Relative Change ◽  
Inp Substrates

AbstractWith X-ray diffraction techniques, it is possible to routinely measure lattice parameters to several parts in 104 for macroscopic specimens. However, measurements of lattice parameter changes for quaternary (InGaAsP) device structures several microns in width are not usually feasible with X-ray diffraction techniques. Convergent Beam Electron Diffraction (CBED), which is one of the techniques available on a modern transmission electron microscope (TEM), may be sensitive to these small, localized lattice parameter changes. Unfortunately, dynamical diffraction effects prevent direct extraction of changes in the lattice parameter from CBED patterns which are obtained from high atomic number materials. For this reason, we have chosen to calibrate the relative position of CBED features with X-ray lattice parameter measurements which were obtained from planar quaternary layers grown on InP substrates. For the active quaternary region of an electro-optical device structure, it is shown that this approach may be sensitive to a relative change in the lattice parameter as small as ±2 parts in 104, which is the uncertainty in the X-ray calibration measurements.

Comparison of Simulated and Experimental Order Parameters in FePt—II

2011 ◽  
Vol 17 (3) ◽  
pp. 403-409 ◽  
Author(s):  
Karen L. Torres ◽  
Richard R. Vanfleet ◽  
Gregory B. Thompson
Keyword(s):  
Electron Diffraction ◽  
Order Parameter ◽  
Convergent Beam Electron Diffraction ◽  
Order Parameters ◽  
X Ray Diffraction ◽  
Chemical Order ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Convergent Beam ◽  
Good Agreement

AbstractEight FePt thin film specimens of various thicknesses, compositions, and order parameters have been analyzed to determine the robustness and fidelity of multislice simulations in determining the chemical order parameter via electron diffraction (ED). The shape of the simulated curves depends significantly on the orientation and thickness of the specimen. The ED results are compared to kinematical scattering order parameters, from the same films, acquired from synchrotron X-ray diffraction (XRD). For the specimens analyzed with convergent beam electron diffraction conditions, the order parameter closely matched the order parameter as determined by the XRD methodology. However, the specimens analyzed by selected area electron diffraction conditions did not show good agreement. This has been attributed to substrate effects that hindered the ability to accurately quantify the intensity values of the superlattice and fundamental reflections.

scholarly journals Influence of Doping on the Crystal Potential of Silicon investigated by the Convergent Beam Electron Diffraction Technique

1980 ◽  
Vol 35 (9) ◽  
pp. 973-984 ◽  
Author(s):  
R. Voss ◽  
G. Lehmpfuhl ◽  
P. J. Smith
Keyword(s):  
Electron Diffraction ◽  
Excellent Agreement ◽  
Convergent Beam Electron Diffraction ◽  
Index Structure ◽  
Beam Electron ◽  
X Ray ◽  
Crystal Potential ◽  
Small Crystal ◽  
Electron Diffraction Technique ◽  
Convergent Beam

Abstract Low index structure potentials of silicon were determined by convergent beam electron diffraction (Kossel-Möllenstedt technique) from very small crystal areas of about 100 Å in diameter. The values of 111, 222, 220, 113 and 004, determined to an accuracy of ±0.03 volts, are in excellent agreement with the accurate X-ray results of Aldred and Hart (see [6], p. 239). Heavy arsenic or phosphorous doping was found to cause a shift of 0.15 volts in the 111 structure potential. Absorption potentials were also determined and found to be 1/3 of the theoretical values published by Radi [20].

Thickness dependence of the intensities of the 200 forbidden reflections in the TiBe2 diamond type structure

1988 ◽  
Vol 46 ◽  
pp. 826-827
Author(s):  
Dang-Rong Liu ◽  
D. B. Williams
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Convergent Beam Electron Diffraction ◽  
Type Structure ◽  
Beam Electron ◽  
Space Group ◽  
X Ray ◽  
Electron Diffraction Technique ◽  
Convergent Beam ◽  
Diamond Type

It is interesting to note that for the diamond type structure of Si, Ge and diamond, the forbidden {200} reflections in the exact <100> orientation diffraction pattern cannot be seen. In contrast, we also note a standing controversy over the structure of the MgAl2O4, spinel. Its structure was determined long ago by x-ray powder method as Fd3m (the diamond type). However, its electron diffraction pattern taken in the <100> orientation shows weak {200} reflections, which are taken as evidence that the spinel should have the space group F43m (the blende type), rather than Fd3m. Others speculate that these {200} reflections result from the high order Laue zone (HOLZ) reflections, and the spinel should be Fd3m. Nevertheless, still others think that these analyses are not conclusive. We have carefully studied the space group of TiBe2 using the convergent beam electron diffraction technique, and unambiguously demonstrated that its space group must be Fd3m.

Dislocations in YBa2Cu3O7−δ (δ = 0.77)

1990 ◽  
Vol 48 (4) ◽  
pp. 72-73
Author(s):  
Yimei Zhu ◽  
Hong Zhang ◽  
A.R. Moodenbaugh ◽  
M. Suenaga
Keyword(s):  
Electron Microscope ◽  
Electron Diffraction ◽  
Displacement Vector ◽  
Stacking Faults ◽  
Spot Size ◽  
Convergent Beam Electron Diffraction ◽  
Burgers Vector ◽  
Beam Electron ◽  
X Ray ◽  
Convergent Beam

Abundant dislocations and dislocations associated with stacking faults were observed and characterized in YBa2Cu3O7−δ (δ= 0.77). The crystallographic orientation of the dislocation and the fault were analyzed using Kikuchi patterns matched with computer generated Kikuchi maps. The Burgers vector of the dislocation and the displacement vector of the fault were determined by using the g·b = 0 and g · R=0 criteria.Bulk samples of YBa2Cu3O7 were produced by standard pressing and sintering up to 970 °C. Samples were heated in air, then quenched into liquid nitrogen to reduce oxygen content. Subsequent anneal at 200 ° C took place with samples sealed in silica with 1/2 atm. of argon. TEM specimens were thinned by ion mill and examined in a JEOL 2000FX electron microscope operating at 200kv.X-ray powder diffraction and convergent beam electron diffraction with 200 Å spot size show that YBa2Cu3O6.23 has a tetragonal structure.

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