Neutron and X-ray diffraction study of LiRh

Abstract

A study of the crystal structure of LiRh was made by combined neutron and X-ray diffraction techniques to determine unambiguously the positions of lithium atoms in the unit cell. The unit cell is hexagonal; space group P(;; a0=2.649+0.003, c0=4"357+0"002 A, with one Rh at (0,0,0) and one Li at (½, ], ½) and calculated density o= 6.88 g.cm -3. Rh atoms are in one layer and Li in the other, the layers alternating along the c axis at co/2 distance apart. The interatomic distances are Rh-Rh = 2-649, Li-Li=2.649 and Rh-Li= 2.663 A.

Interaction of slow neutrons with natural Rutenium, Rhodium, Cadmium and Thallium and some of their isotopes

“…From RhC13 we received the coherent Rh-scattering length b = 5.90 _+ 0.04fm (Table 1), which is in good agreement with the early measurements of Sidhu [20] (b = 5.91_+ 0.04 fm) and of Shirane [21] (b=5.85+_ 0.05 fm).…”

Crystal Structure of LiRh‐type IrZn Determined by Powder X‐ray and Selected Area Electron Diffraction

“…A small compression of the c/a ratio of 1.527 relative to the ratio of 1.633 for a closest packing of hard spheres comes along with closer contacts between unlike [264.5(1) pm] than like atoms [276.3(1) pm]. Thus, the structure is isotypic with Li M phases ( M = Rh, Ir, Pd, Pt; in the case of M being Pd or Pt also an ω‐type phase Li 2 M exists, similar to IrZn 2 ) . As seen from Figure B the atoms have a trigonal prismatic coordination by the unlike species as in the related WC‐type structure .…”

“…Thus, uncovering a new structure in a series of equiatomic phases offers an exquisite opportunity to identify rivaling interatomic interactions favoring one modification over another . In the course of our investigations concerning the phase relations in binary platinum metal‐zinc systems we found IrZn which contrary to the homologous phase RhZn (CsCl type) adopts a LiRh‐type structure …”

New quaternary carbide Mg1.52Li0.24Al0.24C0.86as a disorder derivative of the family of hexagonal close-packed (hcp) structures and the effect of structure modification on the electrochemical behaviour of the electrode

“…5) shows that the title carbide belongs to the family of hcp structures in which the parent structure is the Mg type. By means of ordered and partial substitution from the hcp Mg-type via translationengleiche symmetry reduction of index 2 (Bä rnighausen, 1980), the LiRh (Sidhu et al, 1965) structure type and an Mg 2-2x -Li x Al x (Rudajevová et al, 2003;Pavlyuk et al, 2016) solidsolution phase can be obtained, respectively. The subsequent insertion of the smallest atoms into the ordered (LiRh) and disordered (Mg 2-2x Li x Al x ) phases gave the TlCdS 2 (Guseinov et al, 1967) Scanning electron microscopy (SEM) image of (a) the Mg 1.52 -Li 0.24 Al 0.24 + 30 wt% MWCNT sample and (b) the formation of single crystals of the carbide phase shown in the enlarged image.…”