Diffuse x-ray scattering near Bragg peaks from point defects in a general lattice

Pramana ◽  
1983 ◽  
Vol 20 (4) ◽  
pp. 279-286 ◽  
Author(s):  
Rita Khanna
Keyword(s):  
Point Defects ◽  
General Lattice ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Diffuse X-ray scattering measurements of point defects and clusters in iron

2007 ◽  
Vol 367-370 ◽  
pp. 269-275 ◽  
Author(s):  
R.E. Stoller ◽  
F.J. Walker ◽  
E.D. Specht ◽  
D.M. Nicholson ◽  
R.I. Barabash ◽  
...  
Keyword(s):  
Point Defects ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Measurements ◽  
Ray Scattering

X-Ray Scattering from the Displacement Field of Point Defects

1972 ◽  
Vol 29 (4) ◽  
pp. 224-226 ◽  
Author(s):  
H. Lohstöter ◽  
H. Spalt ◽  
H. Peisl
Keyword(s):  
Point Defects ◽  
Displacement Field ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Study of point defects in as-grown and annealed bismuth germanate single crystals

2005 ◽  
Vol 38 (3) ◽  
pp. 448-454 ◽  
Author(s):  
G. Bhagavannarayana ◽  
A. Choubey ◽  
Yu. V. Shubin ◽  
Krishan Lal
Keyword(s):  
Point Defect ◽  
Single Crystals ◽  
Point Defects ◽  
Bismuth Germanate ◽  
Cluster Radius ◽  
X Ray ◽  
Defect Clusters ◽  
X Ray Scattering ◽  
Point Defect Clusters ◽  
Ray Scattering

Point defects and their clusters in bismuth germanate single crystals free from grain boundaries and having low density of dislocations were studied by high-resolution diffuse X-ray scattering measurements. Differences in defects in the colourless crystals (type A) and the crystals having yellow tinge (type B), which were grown with different raw materials, were investigated. In addition, interesting differences in defect structures in specimens from different regions of the same boule were investigated. Specimens with diffracting surfaces along (111), (112) and (100) planes were studied. A multicrystal X-ray diffractometer employing a well collimated and highly monochromated Mo Kα1 beam and set in (+,−,−,+) configuration was employed. The diffraction curves of all the samples were quite narrow with half-widths in the range 7–11 arcsec, which are close to the theoretically expected values, if instrumental broadenings are taken into account. The observed distribution of diffuse X-ray scattering (DXS) intensity showed that not all the point defects are isolated but a significant fraction are agglomerated into clusters. Experimental data of DXS intensity were analysed by using a phenomenological model for a small concentration of dislocation loops wherein the point defects are loosely clustered with weak interactions among them. From this analysis, the cluster radius R cl, cluster volume A cl, the number of point defects within a cluster N cl and the relative concentration of the point-defect clusters among the samples were estimated. It was observed that cluster sizes do not vary from sample to sample. However, it was found that the concentration of clusters is approximately twice in the coloured sample compared with that of the colourless sample from the same boule. Annealing of the crystals at 1273 K produced an increase in point-defect clusters by a factor of ∼200. It was accompanied by a reduction in volume of clusters by a factor of ∼0.14.

Sign in / Sign up

Export Citation Format

Share Document