Metal Pnictides: Structures and Thermoelectric Properties

Assoud, Abdeljalil; Kleinke, Holger

doi:10.1002/9783527691036.hsscvol1012

Cited by 3 publications

(3 citation statements)

References 130 publications

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“…The charge compensation by X 3 4À anions seems less favorable for X = S or Se, as no polysulfides and polyselenides of the composition REX 1.8 are known to date, although at least examples for linear Se 3 4À anions in the solid state have been reported. [62] The high defect density in the tellurides RETe 1.8 comes along with two adjacent anion vacancies in their Te layers or, in other words, one missing Te 2 2À anion. Such a pattern, being absent in the chalcogenides REX 1.9 , is emerging in some disordered REX 1.875 � δ' structures and will be seen again in the incommensurately modulated compounds RETe 1.84 (2) .…”

Section: Tellurides Rete 18mentioning

confidence: 99%

Superstructures and Chemical Bonding in Rare Earth Metal Polytellurides RETe_2‐δ (RE=La−Nd; Sm−Tm; 0≤δ≤0.2)

Doert

Poddig

Finzel

2023

Zeitschrift anorg allge chemie

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Polychalcogenides REX2‐δ (X=S, Se, Te; 0≤δ≤0.2) of trivalent rare earth metals RE have been investigated in recent years to shed light on the structural diversity as a function of compositional, metric, thermodynamic, and electronic situation. Whereas the former aspects have comparable influence on the structures of all polychalcogenides REX2‐δ, the bonding situation was assumed different for tellurides due to tellurium's higher tendency to delocalize electrons. The crystal structures generally contain puckered [REX] double slabs and planar [X] layers, the latter hosting different distortions from a square‐like arrangement. The distortion patterns of sulfides and selenides can be understood by a Zintl‐type approach; they are dominated by localization of valence electrons in mono‐ (X2−) or dinuclear (X22−) anions only. This review discusses crystal structures of some rare‐earth metal polytellurides RETe2‐δ (0≤δ≤0.2) and bonding features in the chalcogenide layers and relates them to their sulfide and selenide counterparts.

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Section: Tellurides Rete 18mentioning

confidence: 99%

Superstructures and Chemical Bonding in Rare Earth Metal Polytellurides RETe_2‐δ (RE=La−Nd; Sm−Tm; 0≤δ≤0.2)

Doert

Poddig

Finzel

2023

Zeitschrift anorg allge chemie

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“…The II–IV–V 2 ternary pnictides have been studied theoretically and experimentally for their potential applications in optoelectronic devices, including solar cells, due to their stability, dopability, high carrier mobility, and favorable optical absorption/emission properties. − Some of these properties also make them interesting materials for thermoelectric applications. Pnictide compounds often exhibit favorable electronic structures that enhance electrical transport, such as the coexistence of flat and highly dispersive bands near the Fermi level, which has motivated previous investigations of their thermoelectric properties. − …”

Section: Introductionmentioning

confidence: 99%

Theoretical Investigation of the Lattice Thermal Conductivities of II–IV–V₂ Pnictide Semiconductors

Posligua,

Plata,

Márquez

et al. 2023

ACS Appl. Electron. Mater.

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Ternary pnictide semiconductors with II−IV−V 2 stoichiometry hold potential as cost-effective thermoelectric materials with suitable electronic transport properties, but their lattice thermal conductivities (κ) are typically too high. Insights into their vibrational properties are therefore crucial to finding strategies to reduce κ and achieve improved thermoelectric performance. We present a theoretical exploration of the lattice thermal conductivities for a set of pnictide semiconductors with ABX 2 composition (A = Zn, Cd; B = Si, Ge, Sn; and X = P, As) using machine-learning-based regression algorithms to extract force constants from a reduced number of density functional theory simulations and then solving the Boltzmann transport equation for phonons. Our results align well with available experimental data, decreasing the mean absolute error by ∼3 W m −1 K −1 with respect to the best previous set of theoretical predictions. Zn-based ternary pnictides have, on average, more than double the thermal conductivity of the Cd-based compounds. Anisotropic behavior increases with the mass difference between A and B cations, but while the nature of the anion does not affect the structural anisotropy, the thermal conductivity anisotropy is typically higher for arsenides than for phosphides. We identify compounds such as CdGeAs 2 , for which nanostructuring to an affordable range of particle sizes could lead to κ values low enough for thermoelectric applications.

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“…Pnictogen-containing transition-metal carbonyls have recently been the subjects of systematical study and review. ,, It is known that the transition-metal pnictides serve as good semiconductors, as well as thermoelectric and magnetic materials, and the preparation of single-source precursors with different components of transition metals and pnictogens has become a challenging target for synthetic chemists. In comparison to the well-studied E–Fe (E = Sb, Bi) system, the E–Cr system has been relatively less studied. − With our recent success in isolating the novel Bi–Cr carbonyl trigonal-planar complex, [Bi{Cr(CO) 5 } 3 ] − , from the μ 4 -Bi tetrahedral complex [Bi{Cr(CO) 5 } 4 ] 3– , we attempted to further investigate the analogous Sb–Cr system.…”

Section: Introductionmentioning

confidence: 99%

Low-Valent, Multiply Bonded, Trigonal-Planar Sb Complex: Rational Syntheses, Dual Acidic/Basic Properties, and Unexpected Semiconducting Characteristics

Shieh

Lin

et al. 2020

Inorg. Chem.

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A 4-center, 6π-conjugated, multiply bonded trigonalplanar complex, [Sb{Cr(CO) 5 } 3 ] − (1), was synthesized via the hydride abstraction of [HSb{Cr(CO) 5 } 3 ] 2− (1-H) with HBF 4 •H 2 O, with the release of high yields of H 2 . The oxidation state of the Sb atom in [Et 4 N][1] was well-defined as 0, which was evidenced by Xray photoelectron spectroscopy and X-ray absorption near-edge structure. The distinct color−structure relationship of this low-valent Sb complex 1 toward a wide range of organic solvents was demonstrated, as interpreted by time-dependent density functional theory calculations, allowing the trigonal-planar 1 and the tetrahedral solvent adducts to be probed, revealing the dual acid/base properties of the Sb center. In addition, 1 showed pronounced electrophilicity toward anionic and neutral nucleophiles, even with solvent molecules, to produce tetrahedral complexes [(Nu)Sb{Cr(COCl, Br, I, OH; n = 1, Nu = PEt 3 , PPh 3 , N,N-dimethylformamide (DMF), acetonitrile (MeCN)]. On the contrary, the Fe/Cr hydride complex [HSb{Fe(CO) 4 }{Cr(CO) 5 } 2 ] 2− (2-H) was obtained by treating 1 with [HFe(CO) 4 ] − . Upon hydride abstraction of 2-H with HBF 4 •H 2 O or [CPh 3 ][BF 4 ], a multiply bonded Fe/Cr trigonal-planar complex, [Sb{Fe(CO) 4 }-{Cr(CO) 5 } 2 ] − (2), was produced in which the oxidation coupling Sb 2 -containing complexes [Sb 2 Cr 4 Fe 2 (CO) 28 ] 2− (3-Cr) and [HSb 2 Cr 3 Fe 2 (CO) 23 ] − (3-H) were yielded as final products. Complex 3-Cr exhibited dual Lewis acid/base properties via hydridation and protonation reactions, to form 2-H or 3-H, respectively. Surprisingly, [Et 4 N][1] possessed a low energy gap of 1.13 eV with an electrical conductivity in the range of (1.10−2.77) × 10 −6 S•cm −1 , showing that [Et 4 N][1] was a low-energy-gap semiconductor. The crystal packing, crystal indexing, and density of states results of [Et 4 N][1] further confirmed the efficient through-space conduction pathway via the intermolecular Sb•••O(carbonyl) and O(carbonyl)•••O(carbonyl) interactions of the 1D anionic zigzag chain of 1.

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Metal Pnictides: Structures and Thermoelectric Properties

Cited by 3 publications

References 130 publications

Superstructures and Chemical Bonding in Rare Earth Metal Polytellurides RETe_2‐δ (RE=La−Nd; Sm−Tm; 0≤δ≤0.2)

Superstructures and Chemical Bonding in Rare Earth Metal Polytellurides RETe_2‐δ (RE=La−Nd; Sm−Tm; 0≤δ≤0.2)

Theoretical Investigation of the Lattice Thermal Conductivities of II–IV–V₂ Pnictide Semiconductors

Low-Valent, Multiply Bonded, Trigonal-Planar Sb Complex: Rational Syntheses, Dual Acidic/Basic Properties, and Unexpected Semiconducting Characteristics

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Metal Pnictides: Structures and Thermoelectric Properties

Cited by 3 publications

References 130 publications

Superstructures and Chemical Bonding in Rare Earth Metal Polytellurides RETe2‐δ (RE=La−Nd; Sm−Tm; 0≤δ≤0.2)

Superstructures and Chemical Bonding in Rare Earth Metal Polytellurides RETe2‐δ (RE=La−Nd; Sm−Tm; 0≤δ≤0.2)

Theoretical Investigation of the Lattice Thermal Conductivities of II–IV–V2 Pnictide Semiconductors

Low-Valent, Multiply Bonded, Trigonal-Planar Sb Complex: Rational Syntheses, Dual Acidic/Basic Properties, and Unexpected Semiconducting Characteristics

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Superstructures and Chemical Bonding in Rare Earth Metal Polytellurides RETe_2‐δ (RE=La−Nd; Sm−Tm; 0≤δ≤0.2)

Superstructures and Chemical Bonding in Rare Earth Metal Polytellurides RETe_2‐δ (RE=La−Nd; Sm−Tm; 0≤δ≤0.2)

Theoretical Investigation of the Lattice Thermal Conductivities of II–IV–V₂ Pnictide Semiconductors