CsLiGe, One Compound with Two Complementary Structural Descriptions: Isolated [Ge] Tetrahedral Clusters Coordinated by Li and Cs Cations or One-Dimensional [LiGe] Polyanions Packed within a Matrix of Cs Cations?

Reported are the synthesis and structural characterization of CsLiGe, the first structurally characterized lithium-containing cesium germanide. Single-crystal X-ray diffraction data indicate that CsLiGe crystallizes in an orthorhombic crystal system with the space group (no. 63, Person symbol 32) with unit cell parameters = 6.

Advancing Heteroanionicity in Zintl Phases: Crystal Structures, Thermoelectric and Magnetic Properties of Two Quaternary Semiconducting Arsenide Oxides, EuZnAsO and EuZnAsO.

Two novel quaternary oxyarsenides, EuZnAsO and EuZnAsO, were synthesized through metal flux reactions, and their crystal structures were established by single-crystal X-ray diffraction methods. EuZnAsO crystallizes in the orthorhombic space group , featuring polyanionic ribbons composed of corner-shared triangular [ZnAs] units, running along the [100] direction. The structure of EuZnAsO crystallizes in the monoclinic space group 2/ and its anionic substructure can be described as an infinite "ribbonlike" chain comprised of [ZnAs] trigonal-planar units, although the structural complexity here is greater and also amplified by disorder on multiple crystallographic positions.

Applicability of the Zintl Concept to Understanding the Crystal Chemistry of Lithium-Rich Germanides and Stannides.

With this contribution, we take a new, critical look at the structures of the binary phases LiGe and LiSn. Both are isostructural (centrosymmetric space group 3̅, no. 166), and in their structures, all germanium (tin) atoms are dimerized.

Yet Another Case of Lithium Metal Atoms and Germanium Atoms Sharing Chemistry in the Solid State: Synthesis and Structural Characterization of Ba LiGe.

Several Ba-Li-Ge ternary phases are known and structurally characterized, including the title compound Ba LiGe . Its structure is reported to contain [Ge ] anions that exhibit delocalized bonding with a Hückel-like aromatic character. The Ge atoms are in the same plane with the Li atoms, and if both types of atoms are considered as covalently bonded, [LiGe ] honeycomb-like layers will result.

Lithium metal atoms fill vacancies in the germanium network of a type-I clathrate: synthesis and structural characterization of BaLiGe.

Clathrate phases with crystal structures exhibiting complex disorder have been the subject of many prior studies. Here we report syntheses, crystal and electronic structure, and chemical bonding analysis of a Li-substituted Ge-based clathrate phase with the refined chemical formula BaLiGe, which is a rare example of ternary clathrate-I where alkali metal atoms substitute framework Ge atoms. Two different synthesis methods to grow single crystals of the new clathrate phase are presented, in addition to the classical approach towards polycrystalline materials by combining pure elements in desired stoichiometric ratios.

Synthesis and Crystal Structure of the Zintl Phases NaSrSb, NaBaSb and NaEuSb.

This work details the synthesis and the crystal structures of the ternary compounds NaSrSb, NaBaSb and NaEuSb. They are isostructural and adopt the hexagonal ZrNiAl-type structure (space group 6¯2; Pearson code 9). The structure determination in all three cases was performed using single-crystal X-ray diffraction methods.

Robust three-dimensional type-II Dirac semimetal state in SrAgBi.

Topological semimetals such as Dirac, Weyl or nodal line semimetals are widely studied for their peculiar properties including high Fermi velocities, small effective masses and high magnetoresistance. When the Dirac cone is tilted, exotic phenomena could emerge whereas materials hosting such states are promising for photonics and plasmonics applications. Here we present evidence that SrAgBi is a spin-orbit coupling-induced type-II three-dimensional Dirac semimetal featuring tilted Dirac cone at the Fermi energy.

Electrochemical Flux Synthesis of Type-I NaSi Clathrates: Particle Size Control Using a Solid or Molten Na-Sn Mass Transport Mediator.

Sodium-filled silicon clathrates have a host of interesting properties for thermoelectric, photovoltaic, and battery applications. However, the metastability of the clathrates has made it difficult to synthesize them with the desired morphology and crystallite size. Herein, we demonstrate an electrochemical method whereby NaSi dissolved in a Sn-based flux is converted to the NaSi type-I clathrate using galvanostatic (constant current) oxidation.

Synthesis, crystal and electronic structure of BaLi Cd ( ≈ 2).

A new ternary phase has been synthesized and structurally characterized. BaLi Cd ( ≈ 2) adopts the cubic NaZn structure type (space group , Pearson symbol 112) with unit cell parameter = 13.5548 (10) Å.

Synthesis and structural characterization of the new Zintl phases EuMnBi and YbZnSb.

Two new ternary compounds, EuMnBi and YbZnSb, were synthesized and structurally characterized. The synthesis was achieved either through reactions in sealed niobium tubes or in alumina crucibles by combining the elements in excess molten Sb. Their structures were elucidated using single-crystal X-ray diffraction, and they were determined to crystallize in the orthorhombic space group (no.

Giant Thermoelectric Power Factor Anisotropy in PtSbSn.

We report on the giant anisotropy found in the thermoelectric power factor (σ) of marcasite structure-type PtSbSn single crystal. PtSbSn, synthesized using an ambient pressure flux growth method upon mixing Sb and Sn on the same atomic site, is a new phase different from both PtSb and PtSn, which crystallize in the cubic Pa3̅ pyrite and Fm3̅m fluorite unit cell symmetry, respectively. The large difference in σ for heat flow applied along different principal directions of the orthorhombic unit cell stems mostly from anisotropic Seebeck coefficients.

Synthesis of Type II Ge and Ge-Si Alloyed Clathrates Using Solid-State Electrochemical Oxidation of Zintl Phase Precursors.

Germanium clathrates with the type II structure are open-framework materials that show promise for various applications, but the difficulty of achieving phase-pure products via traditional synthesis routes has hindered their development. Herein, we demonstrate the synthesis of type II Ge clathrates in a two-electrode electrochemical cell using NaGeSi ( = 0, 1) Zintl phase precursors as the working electrode, Na metal as the counter/reference electrode, and Na-ion conducting β″-alumina as the solid electrolyte. The galvanostatic oxidation of NaGe resulted in voltage plateaus around 0.

Structural Complexity and Tuned Thermoelectric Properties of a Polymorph of the Zintl Phase CaCdSb with a Non-centrosymmetric Monoclinic Structure.

The Zintl phase CaCdSb was found to be dimorphic. Besides the orthorhombic CaCdSb (-o), here we report on the synthesis, the structural characterization, and the thermoelectric transport properties of its monoclinic form, CaCdSb (-m), and its Lu-doped variant CaLuCdSb ( ≈ 0.02).

Materials design, synthesis, and transport properties of disordered rare-earth Zintl bismuthides with the -ThP structure type.

The synthesis, structural elucidation, and transport properties of the extended series CaREBi (RE = Y, La-Nd, Sm, Gd-Tm, and Lu; ≈ 1) and CaREBiSb (RE = La, Ho, Er, and Lu; ≈ 1, ≈ 1.5) are presented. Structural elucidation is based on single-crystal X-ray diffraction data and confirms the chemical drive of CaBi with the cubic -ThP structure type (space group 4̄3, no.

Computational design of thermoelectric alloys through optimization of transport and dopability.

Alloying is a common technique to optimize the functional properties of materials for thermoelectrics, photovoltaics, energy storage Designing thermoelectric (TE) alloys is especially challenging because it is a multi-property optimization problem, where the properties that contribute to high TE performance are interdependent. In this work, we develop a computational framework that combines first-principles calculations with alloy and point defect modeling to identify alloy compositions that optimize the electronic, thermal, and defect properties. We apply this framework to design n-type BaSrCdP Zintl thermoelectric alloys.

Structural and Electrochemical Properties of Type VIII BaGaSn Clathrate (δ ≈ 1) during Lithiation.

Clathrates of the tetrel (Tt = Si, Ge, Sn) elements are host-guest structures that can undergo Li alloying reactions with high capacities. However, little is known about how the cage structure affects the phase transformations that take place during lithiation. To further this understanding, the structural changes of the type VIII clathrate BaGaSn (δ ≈ 1) during lithiation are investigated and compared to those in β-Sn with X-ray total scattering measurements and pair distribution function (PDF) analysis.

The Zintl phases InAs (A = Ca, Sr, Ba): new topological insulators and thermoelectric material candidates.

Recently, there has been a lot of interest in topological insulators (TIs), being electronic materials, which are insulating in their bulk but with the gapless exotic metallic state on their surface. The surface states observed in such materials behave as a perfect conductor thereby making them more suited for several cutting-edge technological applications such as spintronic devices. Here, we report the synthesis and structural characterization of the Zintl phases AIn2As2 (A = Ca, Sr, Ba), which could become a new class of TIs.

Structural Uniqueness of the [Nb(As)] Cluster in the Zintl Phase CsNbAs.

The structure of the novel Zintl phase, CsNbAs, is reported for the first time. This compound crystallizes in the monoclinic 2/ space group (no. 14) with eight formula units per cell.

Complex Structural Disorder in the Zintl Phases YbMnSb and YbMnSb.

A systematic investigation of the ternary system Yb-Mn-Sb led to the discovery of the novel phase YbMnSb. Its crystal structure was characterized by single-crystal X-ray diffraction and found to be complex and highly disordered. The average YbMnSb structure can be considered to represent a defect modification of the CaLiMgSb type and to crystallize in the tetragonal 4/ space group (No.

The structure of CeAlGe refined for the first time from single-crystal X-ray diffraction data.

Single crystals of dicerium trialuminium tetragermanide, CeAlGe, have been synthesized from a high-temperature reaction using an eutectic mixture of Al and Ge as a metal flux. Through single-crystal X-ray diffraction it was established that CeAlGe crystallizes in the centrosymmetric space group Cmce (No. 64) with the BaCdBi structure type (Pearson code oC36).

Caught in Action. The Late Rare Earths Thulium and Lutetium Substituting Aluminum Atoms in the Structure of CaAlBi.

Described are two unprecedented cases, where the rare earth metals Tm and Lu partially substitute Al atoms in the structure of the Zintl phase CaAlBi. These are the first examples within this large family where lanthanides replace the atoms of a main group element. Such crystal chemistry has never been observed before in other materials with the same structure.

One Structure, Two Elements-LuGe Superconductor vs Ordinary Metallic Conductor LuSn. A Case Study on How Site-Selective Germanium for Tin Atom Substitution Leads to Modulating of the Charge Distribution.

The substitution of chemically similar elements in a given crystal structure is an effective way to enhance physical properties, but the understanding on such improvements is usually impeded because the substitutions are random, and the roles of the different atoms cannot be distinguished by crystallographic symmetry. Herein, we provide a detailed crystallographic analysis and property measurements for the continuous solid solutions LuGeSn (0 < < 2). The results show that there is no apparent change of the global symmetry, with the end-members LuGe and LuSn, as well as the intermediate LuGeSn compositions adopting the ZrSi type structure (space group , Pearson index 12).

Synthesis, structural characterization, and electronic structure of the novel Zintl phase BaZnP.

The novel Zintl phase dibarium zinc diphosphide (BaZnP) was synthesized for the first time. This was accomplished using the Pb flux technique, which allowed for the growth of crystals of adequate size for structural determination via single-crystal X-ray diffraction methods. The BaZnP compound was determined to crystallize in a body-centered orthorhombic space group, Ibam (No.

Electronic stabilization by occupational disorder in the ternary bismuthide LiInBi (x ≃ 0.14, y ≃ 0.29).

A ternary derivative of LiBi with the composition LiInBi (x ≃ 0.14, y ≃ 0.29) was produced by a mixed In+Bi flux approach.