Lattice of crystal

Like paraldehyde, metaldehyde can be preserved, and, when freshly prepared, is odourless. It also has no aldehydic properties. On keeping, however, a distinct odour of acetaldehyde becomes evident —a sign that here also an equilibrium is slowly being established. Metaldehyde can be completely depolymerised by heating. Molecular weight determinations (in phenol) show that metaldehyde is tetra-molecular (Hantzsch) the examination of the space lattice of crystals by the method of Laue and Bragg points to the same conclusion (Mark). 

It has been mentioned that mole fractions are not always the most convenient composition variables since they often do not take into account particular features and conditions of the crystal structure. Normally, statistical considerations require composition variables which refer to the number of sites in a sublattice rather than to the number of component atoms. Let us discuss a simple example. Component B is dissolved in the interstitial lattice of crystal A. NH = nB/(nA + nB) does not have an immediate statistical meaning. However, if we know from the crystal structure condition that the number of interstitial sites per A-lattice site is miy then the fraction... 

In JP-A-2213174 cross-talk between adjacent photodiodes is reduced by providing a lattice of crystal defects on the surface of a CdTe substrate before an HgCdTe detector layer is grown thereon. 

A lattice of crystal defects 5 are formed on the surface of a CdTe substrate 1 by producing flaws in the surface mechanically by means of a needle or by the use of an electron beam. 

Inorganic Chemistry From the discrete lattice of crystal symmetry to the continuous manifolds of differential geometry... 

The discovery of the diffraction of X-rays by the space lattices of crystals (Max von Laue, 1912), and the resulting determination of crystal structures (W. H. and W. L. Bragg, sincel913), enabled many more structures to be determined within the next decade and, by about 1933, the general rules governing atomic crystal structures were recognized. 

A crystallographic plane (hkl) is represented as a light spot of constructive interference when the Bragg conditions (Equation 2.3) are satisfied. Such diffraction spots of various crystallographic planes in a crystal form a three-dimensional array that is the reciprocal lattice of crystal. The reciprocal lattice is particularly useful for understanding a diffraction pattern of crystalline solids. Figure 2.7 shows a plane of a reciprocal lattice in which an individual spot (a lattice point) represents crystallographic planes with Miller indices (hkl). 

Lattice diffusion is related to the movement of point defects over the lattice of crystal sohds. Lattice diffusion has vacancy mechanism or interstitial mechanism, depending on the type of defects, vacancy or interstitial, which are most important lattice diffusion mechanisms. 

If we examine a crystallographic assay of the lattice of crystallized CO, the molecules may have either the configuration CO or the configuration... 

Cooperative phenomena in lattices of crystal-field split ions... 

We consider a lattice of crystal-field split ions in which some of the ions are replaced by impurities. These impurities can be either other RE-ions with different crystal-field splitting and/or different coupling parameter to the neighbouring ions or they can be ions such as La which act like holes in the lattice due to the absence of 4f electrons. In the following we want to discuss the influence of such impurities on the properties of the otherwise perfect lattice system. We shall divide the problem into two parts. First we shall consider the one impurity problem. Here the changes of the excitation spectrum are of interest (local modes, resonant modes) as well as the possible occurrence of such phenomena as giant moments or giant Jahn-Teller distortions. After this we consider finite impurity concentrations and their effect on the transition temperature. 

---