Crystal structure of a Cu3Au-type compound CeRh3B0.5 studied by high-resolution electron microscopy

Structural variations of ScRh3Bx (x=0–1) phase studied by transmission electron microscopy

“…Namely, no drastic structural change can be detected by the Xray powder diffraction. The diffraction patterns of Fig The 1/2 1/2 1/2-type superlattice reflections lead to a superlattice with a unit cell of 2a c × 2a c × 2a c , having an ordered Ce 4 Rh 12 B 2 -type structure [12], which corresponds to the structure of CeRh 3 B 0.5 . It is reasonable that deficient B atoms in the ScRh 3 B 0.5 and ScRh 3 B 0.75 alloys form the superlattice, but the intensity of the superlattice reflections is relatively strong for ordering of B atoms with a weak atomic scattering factor, even if the dynamical effect of electron beam is considered.…”

“…abrupt drop of hardness, in B content 0.4 < x < 0.5 [12]. Moreover, the authors have studied the crystal structure of CeRh 3 B 0.5 , whose B content corresponds to the range with the anomalous drop of hardness, by electron diffraction and HRTEM [13].…”

Phase equilibria and crystal structures in the system Eu–Pd–B

“…The latter observation is in line with recent studies by electron diffraction and high-resolution transmission electron microscopy of Yubuta et al [8,9] on changes with B content in hardness and oxidation resistance for CeRh 3 B 0.5 and ScRh 3 B y (y ¼ 0.5, 0.75). In both cases, CeRh 3 B y and ScRh 3 B y , tetragonal structure modifications were detected (space group I4/ mmm, a t ¼ b t ¼ a c O2, c ¼ 2c c ) as well as modulations by appearance of fine domains [10,11].…”

Anomalous behavior of hardness and crystal structure in CeRh3Bx (x=0–1) phase

“…The 1/2 1/2 1/2-type superlattice reflections indicate the drastic structural transitions and lead to a superstructure with a unit cell 2a c × 2a c × 2a c , having an ordered Ce 4 Rh 12 B 2 structure [10], which corresponds to the CeRh 3 B 0.5 . It is reasonable that deficient B atoms in the CeRh 3 B 0.5 alloy form the superstructure.…”

“…has new ordered structure producing the superlattice reflections belonging to a tetragonal system, space group I4/mmm (no. 139) and cell parameters with a t = b t = a c √ 2 = 0.5795 nm and c t = 2a c = 0.8196 nm (a c : a lattice constant of the Cu 3 Autype cubic structure) [10]. The proposed tetragonal Ce 4 Rh 12 B 2 structure is characterized by ordering of both B atoms and Rh octahedrons.…”