Lateral lattice parameter variation measurement by means of a double crystal X-ray method with oscillating slit

1984 ◽  
Vol 34 (12) ◽  
pp. 1277-1281 ◽  
Author(s):  
D. Korytár
Keyword(s):  
Lattice Parameter ◽  
Parameter Variation ◽  
Ray Method ◽  
Double Crystal ◽  
X Ray ◽  
Lattice Parameter Variation

Lattice-parameter variation with carbon content of martensite. I. X-ray-diffraction experimental study

1995 ◽  
Vol 52 (14) ◽  
pp. 9970-9978 ◽  
Author(s):  
Liu Xiao ◽  
Zhong Fan ◽  
Zhang Jinxiu ◽  
Zhang Mingxing ◽  
Kang Mokuang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Carbon Content ◽  
Lattice Parameter ◽  
Parameter Variation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Parameter Variation

scholarly journals Evaluation of crystallographic ordering degree of magnetically active ions in Sr 2FeMoO 6-δ by means of the (101) X-ray peak intensity

2019 ◽  
Vol 5 (4) ◽  
pp. 151-157
Author(s):  
Evgenij Artsiukh ◽  
Gunnar Suchaneck
Keyword(s):  
Experimental Data ◽  
Double Perovskite ◽  
Rietveld Analysis ◽  
Lattice Parameter ◽  
Parameter Variation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Parameter Variation ◽  
Peak Intensity ◽  
Ordering Degree

Strontium ferromolybdate double perovskite is a promising candidate for room-temperature spintronic applications. Nevertheless, SFMO has not yet found wide application in spintronics. This is attributed to the low reproducibility of its magnetic properties which partially originates from their strong dependence on the ordering degree of Fe and Mo ions in the Bʹ and Bʺ sublattices of double perovskite A2BʹBʺO6. In this work, we have considered an express method of determining the degree of disorder in strontium ferromolybdate. The sublattice occupation with Fe and Mo ions has been estimated for stoichiometric and nonstoichiometric Sr2FeMoO6-δ with a 5% Fe and Mo excess, respectively. We have calculated the intensity ratio between the superstructure (101) XRD peak and the most intense (112 + 200) peak. The calculated curves have been fitted to an analytical expression of a similar case known from literature. The calculation results obtained using the proposed method are within a ± 25 % agreement with Rietveld analysis of experimental data. Thus, this method can be used as an alternative to Rietveld analysis if the exposure time during X-ray diffraction experiment was insufficient. We have discussed the dependence of the I (101)/I (112 + 200) peak intensity ratio on various factors including instrumental broadening of diffraction peaks, peak twinning due to grain size reduction, thin film lattice parameter variation due to substrate lattice mismatch and lattice parameter variation due to oxygen vacancies. The relevance of the method is the evaluation of the degree of superstructure ordering in Sr2FeMoO6-δ without large time consumption for X-ray diffraction pattern recording and Rietveld data processing which may be essential when dealing with large amounts of experimental data.

On the dilatation of synthetic type Ib diamond by substitutional nitrogen impurity

1991 ◽  
Vol 337 (1648) ◽  
pp. 497-520 ◽  
Keyword(s):  
Infrared Absorption ◽  
Infrared Absorption Spectrum ◽  
Internal Standard ◽  
Optical Microscope ◽  
Lattice Parameter ◽  
Bragg Angle ◽  
Growth Sector ◽  
Double Crystal ◽  
X Ray ◽  
Nitrogen Impurity

Sequences of high Bragg-angle (0 B = 74°) double-crystal X-ray topographs taken at the SRS (Daresbury, U.K.) have yielded precise measurements of lattice parameter differences between growth sectors of different crystallographic forms in a large undoped synthetic diamond whose type Ib infrared absorption spectrum (principal peak at 1130 cm -1 ) indicated atomically dispersed nitrogen, singly substituting for carbon, as the only detectable impurity. The plate-shaped specimen, polished parallel to (110), 5.0 x 3.2 mm 2 in area, 0.7 mm thick, possessed an unusually well developed (110) growth sector containing nitrogen impurity concentration of only ca. 10 -6 , which served as an internal standard of pure-diamond lattice parameter with which lattice parameters of nitrogen-containing growth sectors were compared. The specimen’s suitability for precision diffractometry was checked by comprehensive tests using optical microscope techniques, cathodoluminescence and single-crystal X-ray topography. The double-crystal combination was silicon reference crystal, asymmetric 175 reflection, with diamond specimen symmetrical 440 reflection. The principal measurement was the increase of the lattice parameter, a 0 , of the (111) growth sector (nitrogen content 88 + 7 parts per 10 6 atomic) relative to that of the (110) sector: Aa 0 / a 0 = 1.18 + 0.07 x 10 -5 . In terms of measured infrared absorption coefficient at 1130 cm -1 , this gives Aa 0/a 0 = (2.95 + 0.27) x 10 -6 [p(1130 cm -1 )/cm -1 ], which is believed to hold for growth sectors of all crystallographic forms. Combination with the nitrogen assay findings of Woods, van Wyk & Collins ( Phil. Mag. B 62. 589-595 (1990)) provides a direct relation to c N , the fractional atomic concentration of substitutional nitrogen, as A a 0 / a 0 = (0.14 + 0.02) c N , which indicates that the effective volume of a single substitutional nitrogen atom in diamond is 1.41 +0.06 times that of the carbon atom it replaces. This substantial dilatation conflicts with several models for the substitutional nitrogen structure.

LATTICE PARAMETERS OF MELILITE SOLID SOLUTIONS AND A RECONNAISSANCE OF PHASE RELATIONS IN THE SYSTEM Ca2Al2SiO7 (GEHLENITE) – Ca2MgSi2O7 (AKERMANITE) – NaCaAlSi2O7 (SODA MELILITE) AT 1 000 kg/cm2 WATER VAPOR PRESSURE

1965 ◽  
Vol 2 (6) ◽  
pp. 596-621 ◽  
Author(s):  
A. D. Edgar
Keyword(s):  
Solid Solutions ◽  
Water Vapor Pressure ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
Phase Relations ◽  
Ray Method ◽  
Subsolidus Phase ◽  
X Ray ◽  
Complete Solid Solution ◽  
Temperature Lattice

The extent of melilite solid solutions has been determined for the systems gehlenite–soda melilite, akermanite–soda melilite, and gehlenite–akermanite–soda melilite at 800 °C and 1 000 kg/cm2[Formula: see text] Approximately 50 weight % NaCaAlSi2O7 will form melilite solid solutions with both gehlenite and akermanite but the extent of complete solid solutions in the gehlenite–akermanite–soda melilite system is very limited at this temperature. Lattice parameter determinations of melilite solid solutions indicate that there is a small but significant change in both a and c parameters with increasing soda melilite in the gehlenite–soda melilite system. In the gehlenite–akermanite–soda melilite system, although the range of complete solid solution is very limited, melilites form more than 90% of the products in most compositions and their lattice parameters can be correlated approximately with their bulk compositions, A rapid X-ray method has been developed to determine the approximate compositions of melilites in this system. Comparison is made between the synthetic samples and natural melilites.A reconnaissance of subsolidus phase relations indicates that phase relations are very complex and that only over a very small compositional range can these systems be considered binary or ternary. These studies also indicate that the relations reported by Nurse and Midgley in 1953 should probably be modified. Although the composition NaCaAlSi2O7 does not synthesize only a melilite under the conditions used in this study, it is believed that this is the correct composition of the sodium-bearing end-member.

Sign in / Sign up

Export Citation Format

Share Document