CsCI structure

Abstract—Pseudo-twinning and mechanical twinning have been observed in a transmission electron microscopy study of TiMNi47Fe3 and Ti49Ni5i alloys which have the B2(CsCI) structure. Observation of twinning in ordered alloys is rare and this is the first observation of twinning reported in a B2 structure. The twin planes are the 112 and 114 planes. For 112 pseudo-twins, the composition plane is not the twin plane and the pseudo-twin does not have the B2 structure. For 114 mechanical twins, the composition plane is the twin plane and the twin does have the B2 structure. It is shown that a shear on the 114 plane plus a shuffle of the atoms results in the ordered B2 structure in the twinned region. 

Structures for some common crystal types in which the ratio of cation to anion is 1 1. (a) The NaCI or rock salt structure, (b) The CsCI structure, (c) The zinc blende structure for ZnS. (d) The wurtzite structure for ZnS. 

Recalculate the effective ionic charge Z and transverse charge e for alkali halides in I lie CsCI structure, using the from Table 14-2. 

Figure 27.6 (a) Layer in CsCI structure (b) CsCI structure. 

The CsCI structure is a simple cubic array of chloride ions with a cesium ion at the center of each cubic array (see Exercise 67). Given that the density of cesium chloride is 3.97 g/cm, and assuming that the chloride and cesium ions touch along the body diagonal of the cubic unit cell, calculate the distance between the centers of adjacent Cs and Cl ions in the solid. Compare this value with the expected distance based on the sizes of the ions. The ionic radius of Cs+ is 169 pm, and the ionic radius of Cl is 181 pm. 

Tab. 3.1 Experimental and theoretically predicted lattice parameters (A) for CaO in the [ZnS]/[NaCI]/[CsCI] structure types derived from GGA calculations, ionic radii tables, bond-valence calculations, and volume increments.

The calculated volume per atom Is greater than Zen because the CsCI structure Is less compact than the face-centred-cublc (Ca) or the hexagonal-close-packed (Tl) structures. The experimental volume is much smaller owing to a contraction In the compound formation. 

Magnetic structures of some CsCI structure lanthanide compounds. 

It is a common mistake to identify the CsCI structure as body-centered cubic. Remember that the lattice points used to define a unit cell must all be identical. In this case, they are all Cr ions. CsCI has a simple cubic unit cell. 

Among the alkali halides, the cesium chloride structure is found only in CsCl, CsBr, and Csl at ordinary pressures, but all of the alkali halides except the salts of lithium can be forced into the CsCI structure at higher pressures. It is also adopted by the ammonium halides (except NH F), TICI, TIBr, TICN, CSCN, CSSH, CsSeH, and CSNHi. 

Compounds with CsCI structure 75 6. Hard magnetic materials 197... 

Much information is available concerning the magnetic properties of the equiatomic RB compounds with the CsCI structure. The causes of the popularity of these compounds are perhaps the wide range of possible non-magnetic... 

Fig. 14.12. Paramagnetic Curie temperatures as a function of electron concentration of some pseudobinary systems with the CsCI structure (Buschow et al., 1972). The dashed line is the theoretical RKKY fit. A Alfieri et al. (1966), Sekizawa and Yasukochi (1966b), O Buschow et al. (1972).

Silver. Both silver isotopes also have spin i and small magnetic moments. The Knight shift of Ag was measured by von Meerwall et al. (1975) in LaAg (CsCI structure) between 1.5 and 300 K. The shift is approximately one-half that in silver metal itself. 

The solid points were single phase at 900 °C, the open points had two phases, and open triangles divided into three segments contained three phases at 900 °C, an ordered orthorhombic phase with Cmcm symmetry lies between 25 and 28 at.% Al for Nb contents of 15 to 30 at.%. The phase had an orderd B2 (csCI structure) crystal structure for compositions near the aluminum solubility limit for this phase (approximately 13-15 at.% Al). Disagreement between the p phase boundary compositions and pj, tie-line compositions suggested that equilibration of the p, phase was not achieved in 600 hours at 900 °C over the 10 to 12 at.% Al composition range between the p and O phases. 

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