Crystal structure of R3Ge4 compounds (R Er, Ho, Tm, Lu)

Structure and Properties of Gd3Ge4: The Orthorhombic RE3Ge4 Structures Revisited (RE = Y, Tb−Tm)

“…At the early stages of the structure elucidation, the originally proposed structure (Er 3 Ge 4 type,12a Pearson's symbol oC 28) was assumed to be correct and was adopted for the refinements. The initial cycles with isotropic thermal parameters confirmed the overall suitability of the model and converged to reasonable residuals (R1 and wR2 were about 5 and 10%, respectively).…”

“…The refinement of the experimental conditions using a different flux, in this case Pb, proved successful and led to the discovery of the new Gd 3 Ge 4 compound, the structure and properties of which are the focus of this paper. At first, Gd 3 Ge 4 was presumed to be a new member of the orthorhombic Er 3 Ge 4 structure type (Pearson's symbol oC 28; comprising five other RE 3 Ge 4 phases RE = Y, Tb−Tm); however, several unusual aspects of its structure prompted our attention to the fact that these might have been overlooked in the earlier studies on RE 3 Ge 4 , possibly leaving the description of the structure and bonding incomplete. Indeed, these speculations turned factual when the structures of all known RE 3 Ge 4 compounds (RE = Y, Tb−Tm) were re-examined.…”

Crystal structure and magnetic properties of novel R3Co2.2Si1.8 compounds (R=Y, Gd–Tm)

“…R is a rare-earth, p-element. [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. moment per Co in Tb 3 Co 2.2 Si 1.8 and $3.63, 3.01 and 4.15 m B per Co atom in the Dy-, Ho-, and Er-containing phases, assuming Tb, Dy, Ho and Er take the theoretical R 3 þ moment of 9.72, 10.65, 10.60 and 9.58 m B [6], respectively.…”

“…The W 3 CoB 3 structure is an ordered variant of the Er 3 Ge 4 structure (Cmcm space group), in which one of the Ge sites is taken by the Co atoms. In turn, the Er 3 Ge 4 structure is a member of the large family of the two-layer orthorhombic structures with the Cmcm space group symmetry (Table 1) [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. This family is derived from an orthorhombic distortion of the initial hexagonal rare-earth lattice concomitant with an insertion of transition metals and/or p-element atoms.…”

“…Other phases whose rare-earth sublattices are structurally related to those of rare-earth elements are R 3 Co 3 Ga and Er 3 FeGe 3 (R ¼Y, Pr, Nd, Sm, Gd, Tb, a W 3 CoB 3 -type structure) [7,8]. The W 3 CoB 3 structure is an ordered variant of the Er 3 Ge 4 structure (Cmcm space group), in which one of the Ge sites is taken by the Co atoms.…”