X-ray diffraction spikes of diamond

Abstract

THE quantity 2Φ defined by Yoneda for his own calculations differs from my quantity 2Φ, the definition of which he quotes earlier, by 180°. Consequently his result 132°± 3°becomes, in my notation, 48°± 3°, which is not very different from my 52°. Whether it is superior is very debatable. Yoneda's value increases the discrepancy from the observed spike intensities (relative to that at first order) in the second, third, and fourth orders, without gaining any satisfactory agreement at fifth order, for which he still obtains a stronger spike than at third order, instead of an absent one. I supposed another factor to be present, giving a general falling off of intensity at higher order. Yoneda's calculation does not dispose of the evidence for such a factor, but if such a factor were present, his least squares analysis is less appropriate than my method of calculation, the essential point of which is to give great weight to the location of a minimum (a zero, according to the theory) near the third order. The most remarkable result is the smallness of the change which his method of calculation brings about. © 1961 Nature Publishing Group.