Synthesis of Zintl Phase Metal Silicide Thermoelectric Materials in Magnesium/Zinc Flux.

Zintl phases have potential applications as thermoelectric materials for power generation and cooling owing to their complex crystal structures and unique electronic properties. We carried out reactions of silicon with barium and strontium in excess Mg/Zn flux to synthesize (Ba/Sr)MgSi Zintl phases, investigating the effect of varying Ba/Sr ratio on site mixing and thermoelectric properties. (Ba/Sr)MgSi compounds with 0 < < 3 are charge-balanced Zintl phases which adopt the hexagonal HoNiP structure type (space group 6̅2).

Temperature-Dependent Products in Gallium Flux Reactions of Cerium and Transition Metals.

Reactions of cerium and transition metals in excess molten gallium were carried out, exploring the formation of different cerium intermetallics as the flux reaction is cooled. Ce//Ga reactions with = Ni, Cu, Pd, Ag, and Zn produce a high-temperature product, which converts into a low-temperature product in the flux. The phases present in the flux mixture were determined by quenching identical reactions at 750 and 300 °C and identifying the isolated products using elemental analysis and X-ray diffraction.

Metal Flux Growth of Lanthanide Carbide Hydrides Using Anthracene.

Reactions of anthracene in Ln/T eutectic mixtures (Ln = La, Yb; T = Ni, Cu) have produced crystals of new complex lanthanide carbide hydride phases. The thermal decomposition of anthracene provides a source of both carbon and hydrogen. LaCH forms in space group with unit cell parameters = 7.

Flux Growth of an Intermetallic with Interstitial Fluorides Decomposition of a Fluorocarbon.

La(FeC)F was grown as large crystals by reacting iron in a La/Ni eutectic flux in the presence of decafluorobiphenyl (CF) which acts as both a carbon and fluoride source. This mild fluorinating technique enables the isolation of an intermetallic product containing fluoride interstitials, as opposed to forming ionic metal fluorides. The compound adopts a structure in the hexagonal crystal system with space group 6̅ which features FeC units composed of a central iron atom coordinated by three ethylenide units in a trigonal planar configuration.

Flux Growth of Cerium Nickel Gallides Studied by In Situ Neutron Diffraction.

Reactions of cerium and nickel in excess molten gallium were monitored by neutron diffraction during heating and cooling. The formation of binary intermediates CeGa and NiGa was observed during heating. During cooling of the molten mixture from 900 °C, precipitation of BaAl-type CeNiGa occurred at 850 °C.

AnTAlSi (An = Ce, Th, U, Np; T = Ni, Co): Actinide Intermetallics with Disordered GdFeSi Structure Type Grown from Metal Flux.

AnTAlSi (An = Ce, Th, U, Np; T = Ni, Co) were synthesized in metal flux reactions carried out in aluminum/gallium melts. In previous work, UTAlSi (T = Co, Ni) analogues were formed by arc-melting U:T:Si and reacting this mixture in Al/Ga flux. However, in the current work, all compounds were synthesized by using AnO reactants, taking advantage of the ability of the aluminum in the flux to act as both solvent and reducing agent.

Flux Synthesis of a Metal Carbide Hydride Using Anthracene As a Reactant.

La(FeC)H was synthesized from the reaction of iron and anthracene in La/Ni eutectic flux. Anthracene was the source of both the carbon and hydrogen in the product. The structure of this metal carbide hydride features hydride ions in tetrahedral interstitial sites surrounded by lanthanum ions, which was confirmed by single-crystal neutron diffraction studies.

Structural Disorder in Intermetallic Boride PrMTeB (M = Mn, Fe): A Transition Metal Cluster and Its Evil Twin.

Reactions of boron, tellurium, and either iron or manganese in a praseodymium-nickel flux led to the production of PrMTeB (M = Fe or Mn) with a novel structure type that features MB clusters surrounded by a Pr/Te framework. Due to disorder in the orientation of the transition metal boride clusters, these phases initially appear to form in the cubic space group 3̅. However, analysis of site occupancy, bond lengths, and local structure in the MB sublattice indicates the local symmetry is 4̅3.

Flux Synthesis of MgNiBi and Its Structural Relationship to NiBi.

MgNiBi was grown from the reaction of magnesium and nickel in excess bismuth flux. It forms as large, malleable crystals with a new structure type in orthorhombic space group . The structure contains a building block common to Ni-Bi binary phases-nickel zigzag chains running along one direction and surrounded by bismuth.

UTAlSi (T = Ni, Co): Complex Uranium Silicides Grown from Aluminum/Gallium Flux Mixtures.

Two new quaternary analogs of the GdFeSi structure type were grown from the reaction of uranium, silicon, and a transition metal (nickel or cobalt) in an excess of aluminum/gallium flux. The use of a mixed flux was found to be necessary for the formation of UTAlSi (T = Ni, Co). Single crystal X-ray diffraction data shows the presence of disordered U/Si layers that are characteristic of this structure type; precession photographs indicate partial formation of a superstructure and stacking disorder along the -axis.

In Situ Neutron Diffraction Studies of the Metal Flux Growth of Ba/Yb/Mg/Si Intermetallics.

The Ba/Yb/Mg/Si intermetallic system is extremely complex, with four competing structurally related compounds forming from reactions of barium, ytterbium, and silicon in magnesium-rich Mg/Al flux. In addition to the previously reported BaYbMgSi, BaYbMgSi, and BaYbMgSi, a new compound has been found. BaYbMgSi crystallizes in the P6̅ space group, with the ZrNiP structure type.

PrFeMC Versus PrFeMC (M = Si, P; M' = Si, Ge, Sn): Competing Intermetallic Carbides Grown from a Pr/Ni Flux.

Reactions of silicon, carbon, and iron in a low-melting flux mixture of praseodymium and nickel produced two competing intermetallic compounds. PrFeSiC has a new structure type in tetragonal space group P4/ mmm ( a = 15.584(2) Å, c = 11.

Clusters, Assemble: Growth of Intermetallic Compounds from Metal Flux Reactions.

Metal flux synthesis involves the reaction of metals and metalloids in a large excess of a low-melting metal that acts as a solvent. This technique makes use of an unusual temperature regime (above the temperatures used for solvothermal methods and below the temperatures used in traditional solid state synthesis) and facilitates the growth of products as large crystals. It has proven to be a fruitful method to discover new intermetallic compounds.

Switching on a Spin Glass: Flux Growth, Structure, and Magnetism of LaMnNiAlSn Intermetallics.

Reactions of tin and manganese in a lanthanum/nickel eutectic melt in alumina crucibles produce LaMnNiAlSn (0 ≤ x ≤ 3.6; 2.5 ≤ y ≤ 4.

Structural and Optical Properties of Sb-Substituted BiSI Grown from Sulfur/Iodine Flux.

Bismuth and antimony were reacted in sulfur/iodine flux mixtures at various temperatures and iodine concentrations to explore the effects of these variables on the synthesis and properties of BiSbSI products. The products grow as crystals; microprobe elemental analysis and UV/vis/NIR spectroscopy of the BiSbSI solid solutions indicate that substitution is homogeneous within individual crystals but varies up to 15% between crystals within each synthesis batch. Raman spectra show a two-mode behavior upon substitution, indicating covalent bonding within the structure, and TEM/SEM data confirm no presence of nanoclustering or segregation within the crystals.

Low-Dimensional Nitridosilicates Grown from Ca/Li Flux: Void Metal CaInSiN and Semiconductor CaSiNH.

Reactions of indium and silicon with lithium nitride in Ca/Li flux produce two new nitridosilicates: CaInSiN (orthorhombic, Ibam; a = 12.904(1) Å, b = 9.688(1) Å, c = 10.

Mercouri G. Kanatzidis: Excellence and Innovations in Inorganic and Solid-State Chemistry.

Over the last 3-4 decades, solid-state chemistry has emerged as the forefront of materials design and development. The field has revolutionized into a multidisciplinary subject and matured with a scope of new synthetic strategies, new challenges, and opportunities. Understanding the structure is very crucial in the design of appropriate materials for desired applications.

Metal Nitrides Grown from Ca/Li Flux: Ca6Te3N2 and New Nitridoferrate(I) Ca6(LixFe1-x)Te2N3.

Two new tellurium-containing nitrides were grown from reactions in molten calcium and lithium. The compound Ca6Te3N2 crystallizes in space group R3̅c (a = 12.000(3)Å, c = 13.

Ca12InC13-x and Ba12InC18H4: alkaline-earth indium allenylides synthesized in AE/Li flux (AE = Ca, Ba).

Two new complex main-group metal carbides were synthesized from reactions of indium, carbon, and a metal hydride in metal flux mixtures of an alkaline earth (AE = Ca, Ba) and lithium. Ca(12)InC(13-x) and Ba(12)InC(18)H(4) both crystallize in cubic space group Im3̅ [a = 9.6055(8) and 11.

LiCa₃As₂H and Ca₁₄As₆X₇ (X = C, H, N): two new arsenide hydride phases grown from Ca/Li metal flux.

The reaction of arsenic with sources of light elements in a Ca/Li melt leads to the formation of two new arsenide hydride phases. The predominant phase Ca14As6X7 (X = C(4-), N(3-), H(-)) exhibits a new tetragonal structure type in the space group P4/mbm (a = 15.749(1) Å, c = 9.

Synthesis, crystal structure, and magnetic properties of novel intermetallic compounds R2Co2SiC (R = Pr, Nd).

The intermetallic compounds R2Co2SiC (R = Pr, Nd) were prepared from the reaction of silicon and carbon in either Pr/Co or Nd/Co eutectic flux. These phases crystallize with a new stuffed variant of the W2CoB2 structure type in orthorhombic space group Immm with unit cell parameters a = 3.978(4) Å, b = 6.

Flux growth and magnetoresistance behavior of rare earth Zintl phase EuMgSn.

Reactions of europium and tin in 1:1 Mg/Al mixed flux produce large crystals of EuMgSn. This phase crystallizes with the TiNiSi structure type in orthorhombic space group Pnma (a = 8.0849(7) Å, b = 4.

Ca11E3C8 (E = Sn, Pb): new complex carbide Zintl phases grown from Ca/Li flux.

New carbide Zintl phases Ca(11)E(3)C(8) (E = Sn, Pb) were grown from reactions of carbon and heavy tetrelides in Ca/Li flux. They form with a new structure type in space group P2(1)/c (a = 13.1877(9)Å, b = 10.