Description and peak-position determination of a single X-ray diffraction profile for high-accuracy lattice-parameter measurements by the Bond method. I. An analysis of descriptions available

1993 ◽  
Vol 49 (1) ◽  
pp. 106-115 ◽  
Author(s):  
E. Gałdecka
Keyword(s):  
Lattice Parameter ◽  
Peak Position ◽  
High Accuracy ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
Position Determination ◽  
X Ray ◽  
Bond Method

High-precision absolute lattice parameter determination of SrTiO3, DyScO3 and NdGaO3 single crystals

2012 ◽  
Vol 68 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Martin Schmidbauer ◽  
Albert Kwasniewski ◽  
Jutta Schwarzkopf
Keyword(s):  
High Resolution ◽  
High Precision ◽  
Room Temperature ◽  
Systematic Errors ◽  
Lattice Parameter ◽  
Parameter Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Method

The lattice parameters of three perovskite-related oxides have been measured with high precision at room temperature. An accuracy of the order of 10−5 has been achieved by applying a sophisticated high-resolution X-ray diffraction technique which is based on the modified Bond method. The results on cubic SrTiO3 [a = 3.905268 (98) Å], orthorhombic DyScO3 [a = 5.442417 (54), b = 5.719357 (52) and c = 7.904326 (98) Å], and orthorhombic NdGaO3 [a = 5.428410 (54), b = 5.498407 (55) and c = 7.708878 (95) Å] are discussed in view of possible systematic errors as well as non-stoichiometry in the crystals.

scholarly journals VISUALISASI STRUKTUR KRISTAL KERAMIK PEROVSKITE MENGGUNAKAN VESTA

2018 ◽  
Vol 15 (1) ◽  
pp. 46
Author(s):  
Sundami Restiana ◽  
Ari Sulistyo Rini
Keyword(s):  
Crystal Structure ◽  
Diffraction Pattern ◽  
Critical Concentration ◽  
Ceramic Materials ◽  
Lattice Parameter ◽  
Peak Position ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Information ◽  
Software Program

Visualization of crystal structures and simulation of X-ray diffraction patterns of perovskite ceramic was successfully performed by VESTA software programs. The purpose of this research is to obtain the relation of lattice parameter, and composition to the diffraction pattern. The software program produces crystal structure information and a representative X-ray diffraction pattern for the ceramic materials. The program needs several input parameters such as the coordinates of each constituent atom, lattice parameters, and space symmetry. The obtained output of the software program are in the form of diffraction pattern graph and crystal structure data which gives the description of the profile and type (phase) of ceramic material. The results showed that the peak position and intensity of the diffraction pattern are influenced by the arrangement of  the atoms within the unit cell. The addition of impurity atoms such as Sr on the Ba side in BaTiO3 causes the BaTiO3 structure changes from Orthorombic (a≠b≠c) to Tetragonal (a=b≠c) structure. Based on the simulation, it can be predicted that the critical concentration of the change of structure occur at Sr concentration about 0.4.

X-Ray Diffraction Profile Analysis for the Determination of the Crystal Structure of BaTiO3

1980 ◽  
Vol 19 (9) ◽  
pp. 1757-1762 ◽  
Author(s):  
Masahiro Tanaka ◽  
Hideshi Fujishita ◽  
Yōichi Shiozaki ◽  
Etsuro Sawaguchi
Keyword(s):  
Crystal Structure ◽  
Profile Analysis ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
X Ray

scholarly journals A first-prototype multi-determinant X-ray constrained wavefunction approach: the X-ray constrained extremely localized molecular orbital–valence bond method

2017 ◽  
Vol 73 (4) ◽  
pp. 312-316 ◽  
Author(s):  
Alessandro Genoni
Keyword(s):  
Valence Bond ◽  
Resonance Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Localized Molecular Orbitals ◽  
Structure Factors ◽  
Different Temperatures ◽  
Explicit Consideration ◽  
Bond Method

All the current variants of Jayatilaka's X-ray constrained wavefunction (XCW) approach work within the framework of the single-determinant wavefunctionansatz. In this paper, a first-prototype multi-determinant XCW technique is proposed. The strategy assumes that the desired XCW is written as a valence-bond-like expansion in terms of pre-determined single Slater determinants constructed with extremely localized molecular orbitals. The method, which can be particularly suitable to investigate systems with a multi-reference character, has been applied to determine the weights of the resonance structures of naphthalene at different temperatures by exploiting experimental high-resolution X-ray diffraction data. The results obtained have shown that the explicit consideration of experimental structure factors in the determination of the resonance structure weights may lead to results significantly different compared with those resulting only from the simple energy minimization.

scholarly journals Precision X-Ray Stress Analysis of Uranium and Zirconium

1959 ◽  
Vol 3 ◽  
pp. 331-336
Author(s):  
B. J. Wooden ◽  
Lt. E. C. House ◽  
R. E. Ogilvie
Keyword(s):  
Residual Stresses ◽  
Stress Analysis ◽  
Peak Position ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
X Ray ◽  
Least Squares Fit ◽  
Order Polynomial ◽  
Desk Calculator

AbstractThe feasibility of using X-ray diffraction methods to measure residual stresses in uranium and zirconium (Zircaloy-2) was investigated. A precision method was developed for the determination of diffraction peak positions and the precision associated therewith. The statistical tables of Fisher and Yates were used to determine what order polynomial provided the best least squares fit within the known precision of the observed data. It was found that a second-order polynomial provided an adequate regression. With the aid of a desk calculator less than 5 min calculation time is required to determine the peak position to a precision of ±0.01°.The stress constant for uranium was determined to be 1308 ± 110 psi/0.01° shift in Δ2θ for copper radiation on the (116) planes at 2θ = 158.3°. The stress constant for Zircaloy-2 was determined to be 430 ± 1 psi/0.01° shift in Δ2θ for chromium radiation on the (10,4) planes at 2θ = 156.4°.

Lattice parameter dependence versus composition in semiconductor alloys: the InGaAs case

2001 ◽  
Vol 677 ◽  
Author(s):  
C. Ferrari ◽  
E. Villaggi ◽  
N. Armani ◽  
G. Carta ◽  
G. Rossetto
Keyword(s):  
Linear Dependence ◽  
Lattice Parameter ◽  
Semiconductor Alloys ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
X Ray ◽  
Inp Substrate ◽  
Dependence Versus ◽  
Parameter Versus ◽  
Lattice Matched

ABSTRACTFollowing recent works that report a non linear dependence of the lattice parameter versus composition in some semiconductor alloys the InGaAs/InP system has been investigated. The lattice parameter and the composition of InGaAs/InP lattice matched heterostructures have been independently determined by measuring the high resolution X-ray diffraction profile and the absorption of the X-ray beam diffracted from the InP substrate. In contrast with previous results that stated a linear dependence of the lattice parameter with composition, a 6% larger In content in the InGaAs/InP lattice matched alloy is found. Such result has been confirmed by the analysis of the X-ray fluorescence induced by an electron beam on the layer and on standards made of InAs and GaAs fine ground crystals. The result is in good agreement with the predictions of models based on the elasticity theory applied on a microscopic scale.

Quantitative X-Ray Structure Determination of Superlattices and Interfaces

1991 ◽  
Vol 229 ◽  
Author(s):  
Ivan K. Schuller ◽  
Eric E. Fullerton ◽  
H. Vanderstraeten ◽  
Y. Bruynseraede
Keyword(s):  
General Procedure ◽  
Structural Refinement ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
X Ray ◽  
Superlattice Structure ◽  
Wide Range ◽  
Fitting Algorithm ◽  
Superlattice Structures

AbstractWe present a general procedure for quantitative structural refinement of superlattice structures. To analyze a wide range of superlattices, we have derived a general kinematical diffraction formula that includes random, continuous and discrete fluctuations from the average structure. By implementing a non-linear fitting algorithm to fit the entire x-ray diffraction profile, refined parameters that describe the average superlattice structure, and deviations from this average are obtained. The structural refinement procedure is applied to a crystalline/crystalline Mo/Ni superlattices and crystalline/amorphous Pb/Ge superlattices. Roughness introduced artificially during growth in Mo/Ni superlattices is shown to be accurately reproduced by the refinement.

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