Crystal structures, bonding and electronic structures of α- and β-IrB compounds.

The binary boron-rich compounds α-IrB and β-IrB, formerly denoted as α- and β-IrB, were synthesized both arc melting followed by annealing at 800 °C (900 °C) and high-temperature thermal treatment of mixtures of the elements. X-ray structure analysis of α-IrB was performed on a single crystal (space group 2/, = 10.5515(11) Å, = 2.

The Ce-Ni-Si System Revisited: More Homologue Compounds?

The nickel-rich region of the system Ce-Ni-Si has been reinvestigated utilizing X-ray single-crystal, powder, and electron diffraction as well as electron microprobe and thermal analyses. Two novel hexagonal compounds, τ-CeNiSi and τ'-CeNiSi were identified. The crystal structure of τ-CeNiSi was derived from single-crystal X-ray diffraction and found to be isotypic with the SmNiP-type structure (S.

Enhanced thermoelectric properties of In-filled CoSb by dispersion of reduced graphene oxide.

Uniform dispersion of nanosized secondary phases in bulk thermoelectric materials has proven to be an effective strategy to reduce the lattice part of thermal conductivity and improve the thermoelectric efficiency. In this work, reduced graphene oxide (rGO) was uniformly dispersed in the InCoSb bulk material by ultrasonication. The formation of impurity phases of InSb and CoSb in the In-filled CoSb is inevitable, as observed from XRD and EPMA analyses.

Cage compound ScPtB: a Pt-stuffed variant of filled skutterudite structure. Electronic and structural properties.

The title compound was obtained from elements arc melting and its crystal structure was determined from single-crystal X-ray diffraction data (space group 3̄, = 10.2042(6) Å). The refinement indicated the occupancy of icosahedral 2 and cubooctahedral 8 sites solely by Sc atoms which leads to the composition ScPtB in contrast to the previously reported ternary stannides of GdNiSn type (REMSn compounds).

Electronic and Structural Properties of MPtB (M = Y, Yb): Structural Disorder in an Octahedral Boron Framework.

Two new ternary platinum borides, YPtB and YbPtB, were obtained by argon-arc melting of the elements followed by annealing at 780 °C (750 °C). The structures of these compounds combine the fragments of CaB- and AuCu-type structures [space group 3̅; = 1.15, = 4.

LaPdGe and NdPdGe Compounds: Chemical Bonding and Physical Properties.

The two LaPdGe and NdPdGe compounds, crystallizing in the 40-UCoGe crystal structure, were targeted for analysis of their chemical bonding and physical properties. The compounds of interest were obtained by arc melting and characterized by differential thermal analysis, scanning electron microscopy, and X-ray diffraction both on powder and on a single crystal (for the La analogue), to ensure the high quality of the samples and accurate crystallographic data. Chemical bonding was studied by analyzing the electronic structure and effective QTAIM charges of LaPdGe.

Preferential phonon scattering and low energy carrier filtering by interfaces of formed InSb nanoprecipitates and GaSb nanoinclusions for enhanced thermoelectric performance of InCoSb.

Filling the voids of cage forming compounds with loosely bound electropositive elements and by incorporating nano-sized secondary phases are promising approaches to enhance the thermoelectric figure of merit of these materials. Hence, in this work, by combining these two approaches-inserting In into the voids of skutterudite Co4Sb12 as well as dispersing nanoparticles (GaSb)-we have synthesized various samples via ball-milling and spark plasma sintering. InSb as the secondary phase of the matrix, mixed with GaSb, forms the solid solution Ga1-xInxSb.

Enhanced Thermoelectric Performance in the BaCoSb/InSb Nanocomposite Originating from the Minimum Possible Lattice Thermal Conductivity.

The thermoelectric efficiency of skutterudite materials can be improved by lowering the lattice thermal conductivity via the uniform dispersion of a nanosized second phase in the matrix of filled CoSb. In this work, nanocomposites of BaCoSb and InSb were synthesized using ball-milling and spark plasma sintering. The thermoelectric transport properties were studied from 4.

Study of thermal stability of p-type skutterudites DDFeCoSb by Knudsen effusion mass spectrometry.

The temperature and phase stability of p-type skutterudites, DDFeCoSb, manufactured various preparation techniques, all exhibiting a high -level, have been studied by means of thermal analysis and Knudsen effusion mass spectrometry. The results from phase transformation measurements and characteristics of the evaporation of antimony, as the volatile element, supported by microstructure observations and by diffusion profiles are summarized and discussed in view of a full understanding of the degradation processes and knowledge of the long term operation stability of the bulk and nano-structured thermoelectrics studied. It was found out that the antimony evaporation is a complex diffusion kinetic process resulting in a stable Sb level dependent on the preparation route.

Structural and Thermoelectric Properties of Cu Substituted Type I Clathrates Ba₈CuSiGa.

With an attempt to improve the thermoelectric properties of type I clathrates in the Ba-Ga-Si system, we introduce Cu into the framework of the crystal structure. Single crystals are prepared in Ga-flux and characterized by X-ray diffraction techniques and transport measurements for the structural and thermoelectric properties. Our composition analyses show that only a small amount of Cu is determined in the clathrates.

Structure and properties of a novel boride: ThNiB.

Investigation of the system Th-Ni-B prompted a novel ternary compound ThNiB. X-ray structure analysis of single crystals obtained by the mechanical fragmentation of an as-cast sample revealed a fully ordered CeNiB-type structure (space group Cmc2, no. 36; a = 0.

Crystal Chemistry and Thermoelectric Properties of Type-I Clathrate Ba₈NiSiGe ( = 0, 10, 20, 42.2).

Thermoelectric materials are actively considered for waste heat recovery applications. To improve the heat to electricity conversion efficiency, fundamental understanding on composition, crystal structure, and interrelation with the thermoelectric properties is necessary. Here, we report the chemical and thermoelectric properties of type-I clathrates Ba 8 Ni 3.

Thermoelectric properties of CoSb with BiTe nanoinclusions.

The figure of merit (zT) of a thermoelectric material can be enhanced by incorporation of nanoinclusions into bulk material. The presence of bismuth telluride (BiTe) nanoinclusions in CoSb leads to lower phonon thermal conductivity by introducing interfaces and defects; it enhances the average zT between 300-700 K. In the current study, BiTe nanoparticles were dispersed into bulk CoSb by ball-milling.

ScRuB and ScRuB: Borides Featuring a 2D Infinite Boron Clustering.

Two borides, ScRuB and ScRuB, were obtained by argon-arc melting of the elements followed by annealing at 800 °C. ScRuB exhibits a new structure type with the space group Cmcm (a = 3.0195(2) Å, b = 15.

Th Fe -Type Related Structures in Pd(Pt)-Cu-B Systems: Pd CuB -A New Structure Type for Borides.

A new member of the series of Th Fe -type derivative structures, h-(Pd Cu ) B (≡Pd Cu B , unique structure type Pd CuB , space group P6 cm, a=12.9426(9) Å, c=4.8697(4) Å, single-crystal X-ray diffraction (XRD) data) was obtained from as cast alloys and alloys annealed at 600-650 °C.

Yb9+xCuMg4-x (x = 0.034): A κ-Phase Formed by Lanthanoids.

Atom order in the crystal structures of Yb2Cu2-xMg (x = 0.17; Mo2FeB2-type; P4/mbm; a = 0.75592(2) nm; c = 0.

BaAl4 derivative phases in the sections {La,Ce}Ni2Si2-{La,Ce}Zn2Si2: phase relations, crystal structures and physical properties.

Phase relations and crystal structures have been evaluated within the sections LaNi2Si2-LaZn2Si2 and CeNi2Si2-CeZn2Si2 at 800 °C using electron microprobe analysis and X-ray powder and single crystal structure analyses. Although the systems La-Zn-Si and Ce-Zn-Si at 800 °C do not reveal compounds such as "LaZn2Si2" or "CeZn2Si2", solid solutions {La,Ce}(Ni1-xZnx)2Si2 exist with the Ni/Zn substitution starting from {La,Ce}Ni2Si2 (ThCr2Si2-type; I4/mmm) up to x = 0.18 for Ce(Ni1-xZnx)2Si2 and x = 0.

Boron induced structure modifications in Pd-Cu-B system: new Ti2Ni-type derivative borides Pd3Cu3B and Pd5Cu5B2.

The formation of two distinct derivative structures of Ti2Ni-type, interstitial Pd3Cu3B and substitutive Pd5Cu5B2, has been elucidated in Pd-Cu-B alloys from analysis of X-ray single crystal and powder diffraction data and supported by SEM. The metal atom arrangement in the new boride Pd3Cu3B (space group Fd3m, W3Fe3C-type structure, a = 1.1136(3) nm) follows the pattern of atom distribution in the CdNi-type structure.

Pt-B System Revisited: Pt2B, a New Structure Type of Binary Borides. Ternary WAl12-Type Derivative Borides.

On the basis of a detailed study applying X-ray single-crystal and powder diffraction, differential scanning calorimetry, and scanning electron microscopy analysis, it was possible to resolve existing uncertainties in the Pt-rich section (≥65 atom % Pt) of the binary Pt-B phase diagram above 600 °C. The formation of a unique structure has been observed for Pt2B [X-ray single-crystal data: space group C2/m, a = 1.62717(11) nm, b = 0.

Changes in microstructure and physical properties of skutterudites after severe plastic deformation.

The best p-type skutterudites with ZT > 1.1 so far are didymium (DD) filled, Fe/Co substituted, Sb-based skutterudites. DD0.

Thermoelectric properties of a Mn substituted synthetic tetrahedrite.

Tetrahedrite compounds Cu(12-x)Mn(x)Sb4S13 (0 ≤x≤ 1.8) were prepared by solid state synthesis. A detailed crystal structure analysis of Cu10.

Structural and physical properties diversity of new CaCu5-type related europium platinum borides.

Three novel europium platinum borides have been synthesized by arc melting of constituent elements and subsequent annealing. They were characterized by X-ray powder and single-crystal diffraction: EuPt4B, CeCo4B type, P6/mmm, a = 0.56167(2) nm, c = 0.

Influence of Sn-substitution on the thermoelectric properties of the clathrate type-I, Ba8Zn(x)Ge(46-x-y)Sn(y).

A systematic investigation is presented on the influence of Sn-substitution in the clathrate-I compound Ba(8)Zn(x)Ge(46-x-y)Sn(y), particularly for the crystal structure and thermoelectric properties including electrical resistivity, Seebeck coefficient, and thermal conductivity. Two series of samples were prepared to explore the changes for different Sn-contents, (y), and to define the optimum Zn-content, (x), for Ba(8)Zn(x)Ge(46-x-y)Sn(y). Sn-incorporation leads to a linear expansion of the unit cell parameters.

Crystal structure of novel Ni-Zn borides: first observation of a boron-metal nested cage unit: B20Ni6.

The crystal structures of three ternary Ni-Zn borides have been elucidated by means of X-ray single-crystal diffraction (XSC) and X-ray powder diffraction techniques (XPD) in combination with electron microprobe analyses (EMPA) defining the Ni/Zn ratio. Ni(21)Zn(2)B(24) crystallizes in a unique structure type (space group I4/mmm; a = 0.72103(1) nm and c = 1.