Atoms scattering power

In a sense, a superconductor is an insulator that has been doped (contains random defects in the metal oxide lattice). Some of the defects observed via neutron diffraction experiments include metal site substitutions or vacancies, and oxygen vacancies or interstituals (atomic locations between normal atom positions). Neutron diffraction experiments have been an indispensable tool for probing the presence of vacancies, substitutions, or interstituals because of the approximately equal scattering power of all atoms. 

CuZn would be expected, because the scattering powers of the two atoms for slow electrons in the lattice are probably considerably different, even though the scattering powers for fast electrons and for x-rays are very nearly the same. 

The reliability factor B was 0276 after the first refinement and 0-211 after the fourth refinement. The parameters from the third and fourth refinements differed very little from one another. The final values are given in Table 1. As large systematic errors were introduced in the refinement process by the unavoidable use of very poor atomic form factors, the probable errors in the parameters as obtained in the refinement were considered to be of questionable significance. For this reason they are not given in the table. The average error was, however, estimated to be 0-001 for the positional parameters and 5% for the compositional parameters. The scattering power of the two atoms of type A was given by the least-squares refinement as only 0-8 times that of aluminum (the fraction... 

Boron is a light atom. Compared with other atoms in the crystal, B has a relatively stronger scattering power for electrons than that for X-ray. Thus the electron diffraction technique has been successfully applied to study positions of boron atoms in several other crystals [10, 29]. We study the position of B atoms in the crystal of (Yo eCao 4)(SrBa)(Cu2 5B0 5)07 s by means of the image processing technique. 

This is the most useful quantitative intensity formula that may be derived from kinematical theory, since it is applicable to thin layers and mosaic blocks. We add up the scattering from each unit cell in the same way that we added up the scattering from each atom to obtain the stractme factor, or the scattering power of the unit cell. That is, we make allowance for the phase difference r, . Q between waves scattered from unit cells located at different vectors ri from the origin. Quantitatively, this results in an interference function J, describing the interference of waves scattered from all the unit cells in the crystal, where... 

X-ray diffraction studies yield radial distribution function data which are dominated by the much greater scattering power of the more electron-rich oxygen atoms in water. These diffraction results tell us something about... 

In the opposite sitnation, when the carbon is exposed to D O at RH=0.87 in association with a 1 1 (v/v) mixtnre of TH and TD (THD), a large difference is observed with respect to the case where the tolnene is fnlly deuterated (Fig. 6.4, curve 4). I. shows a substantial increase, to 0.11 cm , and the contrast factor also increases as a result of the replacement of deuterium atoms in the toluene (fep=H-0.66 X10 cm) by protons (b -0.37 x 10 cm). It is also noticeable that the accumulated intensity at the peak around 1.7 A is much weaker owing to the reduced scattering power of the TH molecules. 

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