摘要:

A set of experiments has observed the mirror reflection and Bragg diffraction of neutrons at the energy of a low‐lying nuclear resonance of115In. The reflector was a mirror of In metal with the resonance at 1.457 eV. The mirror reflection for different angles of incidence was measured and sets of data showing the relative reflectivities were obtained. For the Bragg diffraction experiment the crystal was a wafer of InP and several examples of Bragg reflections near 1.456 eV were mea

ISSN:1600-5767    

DOI:10.1107/S0021889887009579

出版商:International Union of Crystallography    

年代:1988

数据来源: WILEY

摘要:

Use is made of the theory of dislocation‐induced X‐ray diffraction line broadening in the form presented by Krivoglaz, Martynenko&Ryaboshapka [Fiz. Metall. Metalloved.(1983),55, 5–171 to express the so‐called orientation factors occurring in the relations of diffraction profile parameters (e.g.Fourier coefficients, line widths) in a form which systematically takes into account both the lattice geometry and the elastic behaviour of the scattering crystals. The formalism can be used, in principle, for any materials and types of dislocations. In the case of elastically isotropic media the orientation factors can be described by analytical expressions. The application of the formalism is demonstrated in some detail for various slip systems in hexagonal polycrystals with random orientation of

ISSN:1600-5767    

DOI:10.1107/S0021889887009580

出版商:International Union of Crystallography    

年代:1988

数据来源: WILEY

摘要:

A method is described which assigns indices to a set of single‐crystal reflections recorded by the rotation‐oscillation technique using a fixed X‐ray wavelength. It is assumed that the space group and approximate unit‐cell parameters are known. The unknown crystal orientation is determined directly from the observed diffraction pattern of one or several oscillation data records. A local indexing procedure is described which tolerates large initial errors in the parameters controlling the diffraction pattern. These parameters are refined subsequently, thereby satisfying the constraints imposed by the space‐group

ISSN:1600-5767    

DOI:10.1107/S0021889887009737

出版商:International Union of Crystallography    

年代:1988

数据来源: WILEY

摘要:

X‐ray scattering is used to demonstrate the existence in quartz of an incommensurate phase with a single modulation when a uniaxial stress is applied in theX Yplane. Good agreement with earlier neutron scattering experiments is foun

ISSN:1600-5767    

DOI:10.1107/S0021889887008197

出版商:International Union of Crystallography    

年代:1988

数据来源: WILEY

摘要:

Indexed neutron powder diffraction data of phase II RbNO3indicate a body‐centred cubic unit cell [a= 8.84(3) Å atT= 513 K,V= 690.1(52) Å3,Z= 8,Dx= 2.84(2) Mg m−3,λ= 1.083 Å, possible space groups includeI23,I213,Im3,I432,I3morIm3m] in preference to the previously reported tetragonal cell {a= 6.19,c= 8.74 Å,Z= 4 [Brown&McLaren (1962).Acta Cryst.15, 974–976]}, or trigonal cell {a≃ 5.48,c≃ 10.71 Å,Z= 3 [Ahtee&Hewat (1980).Phys

ISSN:1600-5767    

DOI:10.1107/S0021889887010070

出版商:International Union of Crystallography    

年代:1988

数据来源: WILEY

ISSN:1600-5767    

DOI:10.1107/S0021889887011671

出版商:International Union of Crystallography    

年代:1988

数据来源: WILEY

ISSN:1600-5767    

DOI:10.1107/S0021889888099765

出版商:International Union of Crystallography    

年代:1988

数据来源: WILEY