摘要:

Revised intensity relationships for the three common silicon carbide polytypes (6H, 4Hand 15R) are presented together with the details of a technique by which pure polytype samples may be prepared.

ISSN:1600-5767    

DOI:10.1107/S0021889869006510

出版商:International Union of Crystallography    

年代:1969

数据来源: WILEY

摘要:

An example is reported of a one to one correspondence of dislocations observed by chemical etch pits and by X‐ray topography in a 14 mm diameter silicon sl

ISSN:1600-5767    

DOI:10.1107/S0021889869006522

出版商:International Union of Crystallography    

年代:1969

数据来源: WILEY

摘要:

The refraction of X‐rays may have an effect on the radiographs and topographs of whiskers with a polygonal cross‐section. With the usual diffraction methods there is no perceptible deviation but the phenomenon is visible with the Lang method and perfect crystals, such as whisk

ISSN:1600-5767    

DOI:10.1107/S0021889869006534

出版商:International Union of Crystallography    

年代:1969

数据来源: WILEY

摘要:

A new application of small‐angle scattering of X‐rays to the determination of particle size distributions is discussed, without any hypothesis concerning the shape of these distributions. The practical utilization of this method is described for the case of carbons. In the discussion, a comparison with the results of nitrogen adsorption on an oxidized pile‐grade graphite sample is pres

ISSN:1600-5767    

DOI:10.1107/S0021889869006546

出版商:International Union of Crystallography    

年代:1969

数据来源: WILEY

摘要:

A structure refinement method is described which does not use integrated neutron powder intensities, single or overlapping, but employs directly the profile intensities obtained from step‐scanning measurements of the powder diagram. Nuclear as well as magnetic structures can be refined, the latter only when their magnetic unit cell is equal to, or a multiple of, the nuclear cell. The least‐squares refinement procedure allows, with a simple code, the introduction of linear or quadratic constraints between the paramet

ISSN:1600-5767    

DOI:10.1107/S0021889869006558

出版商:International Union of Crystallography    

年代:1969

数据来源: WILEY

摘要:

The paper describes a method for obtaining consistent estimates of domain size from an evaluation of coefficients derived from curves fitted to the tails of diffraction profiles. An estimate of the mean domain size is computed directly from the intensity data and this is equivalent to the value derived from the slope of the variance‐range function. For many applications this provides a convenient alternative to the method described by Langford&Wilson (Crystallography and Crystal Perfection. London: Academic Press, 1963) but does not replace it. An advantage of the present method is its simplicity and consequent reduction in computing time. It is easier to apply if a computer is not available and is applicable in cases where one or other of the profile tails overlaps that of a neighbouring line. The results obtained by this method are comparable in accuracy to those given by existing technique

ISSN:1600-5767    

DOI:10.1107/S002188986900656X

出版商:International Union of Crystallography    

年代:1969

数据来源: WILEY

摘要:

A commercial pole figure goniometer (Philips) is operated by a process control computer (IBM 1800) with a digital voltmeter to digitize the ratemeter output. The pole density data are stored on disk, and, after processing, are recorded in the pole figure by a plotter attached to the computer. Automatic 2θ–θ powder scans can also be performed without hardware modificat

ISSN:1600-5767    

DOI:10.1107/S0021889869006571

出版商:International Union of Crystallography    

年代:1969

数据来源: WILEY

摘要:

An addendum toJ. Appl. Cryst.(1968).1, 176.

ISSN:1600-5767    

DOI:10.1107/S0021889869006583

出版商:International Union of Crystallography    

年代:1969

数据来源: WILEY

摘要:

Stacking fault densities α and β of the Ag–Pd alloy system were determined from peak shift and peak asymmetry measurements of the X‐ray diffraction line profiles recorded by a Geiger counter X‐ray diffractometer. The concentration of the fault probabilities was found to be small. From Fourier analysis of line shapes the anisotropic values of the effective particle sizes, [Dℯ]

ISSN:1600-5767    

DOI:10.1107/S0021889869006601

出版商:International Union of Crystallography    

年代:1969

数据来源: WILEY

摘要:

The use of the Rachinger correction in line‐broadening studies is discussed. A simplified Stokes correction is shown to be generally vali

ISSN:1600-5767    

DOI:10.1107/S0021889869006613

出版商:International Union of Crystallography    

年代:1969

数据来源: WILEY