Crystal structure of Dy2PdGe6

Грибанов, А. В.; Safronov, Sergey; Мурашова, Е. В.; Seropegin, Yu. D.

doi:10.1016/j.jallcom.2012.07.065

Cited by 7 publications

(6 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The In-flux synthetic route used in this study gave origin to mS36-La 2 AlGe 6 twinned crystals of La 2 PdGe 6 and Pr 2 PdGe 6 , whereas Yb 2 PdGe 6 crystals grown from the same metal solvent are orthorhombic oS72. These results are coherent with recent structural studies on 2 : 1 : 6 germanides assigning to them the oS72 7,9,14,15 or the mS36 model 17 instead of the previously proposed oS18.…”

Section: From R 2 Pdge 6 To R 2 Mge 6 Compounds: Crystallochemical Ansupporting

confidence: 92%

A new glance on R₂MGe₆(R = rare earth metal, M = another metal) compounds. An experimental and theoretical study of R₂PdGe₆germanides

et al. 2017

View full text Add to dashboard Cite

The RPdGe series (R = rare earth metal) was structurally characterized, and the results achieved were extended for a comprehensive study on RMGe (M = another metal) compounds, employing symmetry-based structural rationalization and energy calculations. Directly synthesized RPdGe exists for almost all R-components (R = Y, La-Nd, Sm and Gd-Lu) and even if with La is probably metastable. Several single crystal X-ray analyses (R = Y, Ce, Pr, Nd, Er and Lu) indicated oS72-Ce(GaGe) as the correct structure. The alternative In-flux method, once optimized, produced three good quality RPdGe single crystals: LaPdGe and PrPdGe turned out to be mS36-LaAlGe-type non-merohedrally twinned crystals and YbPdGe is of oS72-Ce(GaGe)-type. The vacancy ordering phenomenon was considered as a possible cause of the symmetry reduction relations connecting the most frequently reported 2 : 1 : 6 structural models (oS18, oS72 and mS36) with the oS20-SmNiGe aristotype. The detected twin formation is consistent with the symmetry relations, which are discussed even considering the validity of the different structural models. DFT total energy calculations were performed for RPdGe (R = Y and La) in the three abovementioned structural models, and for LaMGe (M = Pt, Cu, Ag and Au) in the oS18 and oS72 modifications. The results indicate that the oS18-CeCuGe structure, prevalently proposed in the literature, is associated with the highest energy and thus it is not likely to be realized in these series. The oS72 and mS36 polytypes are energetically equivalent, and small changes in the synthetic conditions could easily stabilize any of them, in agreement with experimental results obtained by direct and flux syntheses.

show abstract

Section: From R 2 Pdge 6 To R 2 Mge 6 Compounds: Crystallochemical Ansupporting

confidence: 92%

A new glance on R₂MGe₆(R = rare earth metal, M = another metal) compounds. An experimental and theoretical study of R₂PdGe₆germanides

et al. 2017

View full text Add to dashboard Cite

show abstract

“…This model was always deduced from X-ray powder diffraction patterns, which are not sensitive to small structural differences. In fact, the crystal structures of (La/Dy/Yb) 2 PdGe 6 and (La/Dy) 2 PtGe 6 , previously reported as oS 18-Ce 2 CuGe 6 , were subsequently reinterpreted as oS 72-Ce 2 (Ga 0.1 Ge 0.9 ) 7 after single-crystal X-ray diffraction analysis. , …”

Section: Introductionmentioning

confidence: 99%

“…In fact, the crystal structures of (La/Dy/Yb) 2 PdGe 6 and (La/Dy) 2 PtGe 6 , previously reported as oS18-Ce 2 CuGe 6 , were subsequently reinterpreted as oS72-Ce 2 (Ga 0.1 Ge 0.9 ) 7 after single-crystal X-ray diffraction analysis. 18,19 (2) This model does not agree with the symmetry principle. 15 According to that, atoms of the same kind have the tendency to occupy the minimal number of equivalent positions in a crystal, a condition not satisfied by Ge atoms in the oS18 model.…”

Section: Introductionmentioning

confidence: 99%

Vacancy Ordering as a Driving Factor for Structural Changes in Ternary Germanides: The New R₂Zn_1–xGe₆Series of Polar Intermetallics (R = Rare-Earth Metal)

et al. 2015

View full text Add to dashboard Cite

Synthesis and structural characterization of the new compounds R2Zn1-xGe6 (R = La-Nd, Sm, Gd-Ho) is reported. A structural change was revealed along this series by careful analysis of single-crystal X-ray diffraction data. For light rare earths up to Tb the orthorhombic oS72-Ce2(Ga0.1Ge0.9)7 model was established; instead, the Dy compound represents a new structure type (P21/m, mP34, Z = 4, a = 7.9613(3) Å, b = 8.2480(4) Å, c = 10.5309(5) Å, β = 100.861(1)°) being a superstructure of the mS36-La2AlGe6 prototype. The established structural models support the increase of Zn deficiency along the series, suggested by microprobe analysis, and its key role in governing structural changes. The vacancy ordering criterion was applied as a successful approach to find a general scheme including the structures of the ∼R2MGe6 compounds known up to now (R = rare-earth metal, M = transition metal, Mg, Al, Ga) and highlighting the subtle structural differences within this family. According to this scheme, these structures are obtained from a common aristotype (oS20-SmNiGe3) via symmetry reduction based on group-subgroup relations accompanied by ordering of vacancies. This approach was optimized with the help of the ToposPro software and extended to the R2Zn3Ge6 series, enriched with new members (R = Sm, Gd-Ho) during this work. Electronic structure calculations on La2ZnGe6 confirm the presence of infinite covalent germanium zigzag chains and three-bonded corrugated layers connected via Zn atoms to form a polyanionic network stabilized by La atoms.

show abstract

“…Among these, the R 2 M Ge 6 constitute a continuously growing family, which has been studied with respect both to crystal structure peculiarities, and physical properties . Recent reports suggest that all these compounds belong to the closely related structure types, oS 72‐Ce 2 (Ga 0.1 Ge 0.9 ) 7 and mS 36‐La 2 AlGe 6 (Figure ). Hereafter the structure types are notated by Pearson symbol‐prototype.…”

Section: Introductionmentioning

confidence: 99%

“…[13][14][15][16][17][18] Among these, the R 2 MGe 6 constitute ac ontinuously growingf amily, [19] which has been studied withr espectb oth to crystal structure peculiarities, [5] and physicalp roperties. [20,21] Recent reports [21][22][23] suggest that all these compounds belong to the closely relateds tructure types, oS72-Ce 2 (Ga 0.1 Ge 0.9 ) 7 and mS36-La 2 AlGe 6 (Figure 1). Hereaftert he structure types are notated by Pearson symbol-prototype.The fact that R 2 MGe 6 compounds exist with variousm etals M (including s-, p-andl ate transition elements) showing only two structuralm odels makes them very attractive for chemical bondings tudies.…”

mentioning

confidence: 97%

Polar‐Covalent Bonding Beyond the Zintl Picture in Intermetallic Rare‐Earth Germanides

Freccero

Solokha

Negri

et al. 2019

Chemistry A European J

View full text Add to dashboard Cite

A comparative chemical bonding analysis for the germanides La2MGe6 (M=Li, Mg, Al, Zn, Cu, Ag, Pd) and Y2PdGe6 is presented, together with the crystal structure determination for M=Li, Mg, Cu, Ag. The studied compounds adopt the two closely related structure types oS72‐Ce2(Ga0.1Ge0.9)7 and mS36‐La2AlGe6, containing zigzag chains and corrugated layers of Ge atoms bridged by M species, with La/Y atoms located in the biggest cavities. Chemical bonding was studied by means of the quantum chemical position‐space techniques QTAIM (quantum theory of atoms in molecules), ELI‐D (electron localizability indicator), and their basin intersections. The new penultimate shell correction (PSC0) method was introduced to adapt the ELI‐D valence electron count to that expected from the periodic table of the elements. It plays a decisive role to balance the Ge−La polar‐covalent interactions against the Ge−M ones. In spite of covalently bonded Ge partial structures formally obeying the Zintl electron count for M=Mg2+, Zn2+, all the compounds reveal noticeable deviations from the conceptual 8−N picture due to significant polar‐covalent interactions of Ge with La and M ≠ Li, Mg atoms. For M=Li, Mg a formulation as a germanolanthanate M[La2Ge6] is appropriate. Moreover, the relative Laplacian of ELI‐D was discovered to reveal a chemically useful fine structure of the ELI‐D distribution being related to polyatomic bonding features. With the aid of this new tool, a consistent picture of La/Y−M interactions for the title compounds was extracted.

show abstract

Crystal structure of Dy2PdGe6

Cited by 7 publications

References 6 publications

A new glance on R₂MGe₆(R = rare earth metal, M = another metal) compounds. An experimental and theoretical study of R₂PdGe₆germanides

A new glance on R₂MGe₆(R = rare earth metal, M = another metal) compounds. An experimental and theoretical study of R₂PdGe₆germanides

Vacancy Ordering as a Driving Factor for Structural Changes in Ternary Germanides: The New R₂Zn_1–xGe₆Series of Polar Intermetallics (R = Rare-Earth Metal)

Polar‐Covalent Bonding Beyond the Zintl Picture in Intermetallic Rare‐Earth Germanides

Contact Info

Product

Resources

About

Crystal structure of Dy2PdGe6

Cited by 7 publications

References 6 publications

A new glance on R2MGe6(R = rare earth metal, M = another metal) compounds. An experimental and theoretical study of R2PdGe6germanides

A new glance on R2MGe6(R = rare earth metal, M = another metal) compounds. An experimental and theoretical study of R2PdGe6germanides

Vacancy Ordering as a Driving Factor for Structural Changes in Ternary Germanides: The New R2Zn1–xGe6Series of Polar Intermetallics (R = Rare-Earth Metal)

Polar‐Covalent Bonding Beyond the Zintl Picture in Intermetallic Rare‐Earth Germanides

Contact Info

Product

Resources

About

A new glance on R₂MGe₆(R = rare earth metal, M = another metal) compounds. An experimental and theoretical study of R₂PdGe₆germanides

A new glance on R₂MGe₆(R = rare earth metal, M = another metal) compounds. An experimental and theoretical study of R₂PdGe₆germanides

Vacancy Ordering as a Driving Factor for Structural Changes in Ternary Germanides: The New R₂Zn_1–xGe₆Series of Polar Intermetallics (R = Rare-Earth Metal)