The determination of the crystal structure of the σ phase in the iron–chromium and iron–molybdenum systems

Abstract

slight spread, but there would not be spherical smoothing to the same extent as in the 5 and 10 A reflexions, which are more numerous and at lower angles. The 1.5/t~ reflexion is, therefore, of considerable significance in deciding between a chain structure and a threedimensional net, and it is more profitable to study the diffraction pattern at high angles rather than the near-origin regions of the Patterson function. If, for example, there are found to be several areas of high intensity on the surface of the 1.5 A sphere in reciprocal space, there is a strong presumption that the structure contains chains parallel to the directions joining these areas to the origin.