ZrNiAl-type gallides with pronounced metal-metal bonding, and the dimorphism of ScPdGa

Heletta, Lukas; Matar, Samir F.; Pöttgen, Rainer

doi:10.1515/znb-2018-0140

Cited by 3 publications

(2 citation statements)

References 53 publications

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“…For ternary intermetallics, the tetragonal body-centered ThCr 2 Si 2 type ( I 4/ mmm ), the orthorhombic TiNiSi type ( Pnma ), or the hexagonal ZrNiAl type ( P 6̅2 m ) representatives show a broad structural and chemical variety resulting in physical properties that can be tuned by their respective elemental combinations. The structures and physical properties of the equiatomic representatives have recently been reviewed. − …”

Section: Introductionmentioning

confidence: 99%

Correlations of Crystal and Electronic Structure via NMR and X-ray Photoelectron Spectroscopies in the RETMAl₂(RE = Sc, Y, La–Nd, Sm, Gd–Tm, Lu; TM = Ni, Pd, Pt) Series

et al. 2019

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A total of 35 intermetallic aluminum compounds have been synthesized from the elements via arc melting and characterized by powder X-ray diffraction. A total of 15 of them have been previously reported; however, detailed property investigations were missing. Compounds of the RETMAl2 (rare earth metal RE = Sc, Y, La–Nd, Sm, Gd–Tm, Lu) series with transition metal TM = Ni, Pd, and Pt crystallize isostructurally in the orthorhombic MgCuAl2 type structure (Cmcm, oC16, fc 2). Single-crystal X-ray diffraction investigations were conducted on YNiAl2, LaNiAl2, YPdAl2, ScPtAl2, and YPtAl2. The TM and Al atoms form a [TMAl2]δ− polyanion, the RE atoms reside in cavities within the framework. While the Sc, Y, La, and Lu compounds exhibit Pauli-paramagnetic behavior, consistent with all atoms being closed shell, the other RETMAl2 compounds show paramagnetism along with magnetic ordering at low temperatures, in line with an open-shell trivalent oxidation state for the RE atoms. Solid-state 27Al NMR investigations were carried out on the Pauli-paramagnetic samples, all showing only a single central transition, in line with one crystallographic site for the respective atoms. The observed quadrupolar coupling constants and electric-field-gradient asymmetry parameters were found to be in good agreement with the density-functional-theory-calculated values. Isotropic resonance shifts are dominated by the Fermi-contact interactions with s-conduction electron densities at the Fermi edge (Knight shifts). The bonding characteristics mirror the electronic density of states and crystal chemistry of the family of intermetallic compounds under consideration. Both the Knight shifts and quadrupolar coupling constants can be predicted based on element-specific increments.

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Section: Introductionmentioning

confidence: 99%

Correlations of Crystal and Electronic Structure via NMR and X-ray Photoelectron Spectroscopies in the RETMAl₂(RE = Sc, Y, La–Nd, Sm, Gd–Tm, Lu; TM = Ni, Pd, Pt) Series

et al. 2019

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“…As can be seen, the x-ray diffraction pattern of HfNiAl, ZrNiAl, and ZrNiGa can be well fitted with ZrNiAl structure type [41,42]. ZrNiAl is an ordered variant of Fe 2 P structure type [41,43].…”

Section: Resultsmentioning

confidence: 71%

Superconductivity in non-centrosymmetric ZrNiAl and HfRhSn-type compounds

Kumar

Luo²,

Du³

et al. 2022

J. Phys.: Condens. Matter

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We report the discovery of superconductivity in non-centrosymmetric compounds HfNiAl, ZrNiAl, ZrNiGa, and HfPtAl by measuring their electrical transport and thermodynamic properties. HfNiAl, ZrNiAl, and ZrNiGa crystallize in the ZrNiAl-type crystal structure, whereas HfPtAl crystallizes in the HfRhSn-type crystal structure. Superconducting transitions for HfNiAl, ZrNiAl, ZrNiGa, and HfPtAl are observed at 1 K, 1.02 K, 0.42 K, and 0.58 K, respectively. Using the Werthamer-Helfand-Hohenberg (WHH) model, the zero-temperature upper critical ﬁelds µ0Hc2(0) were estimated to be 0.58 T, 0.24 T, 0.08 T, and 0.34 T for HfNiAl, ZrNiAl, ZrNiGa, and HfPtAl, respectively. The observed jump in electronic heat capacity ( Ce/γT ) across the superconducting transition is 1.3, 1.39, and 1.27 for HfNiAl, ZrNiAl, and HfPtAl, respectively. After the inclusion of the spin-orbit coupling in the band structure calculations, a total of six bands for ZrNiAl, HfPtAl, and ZrNiGa, and eight bands for HfNiAl were found to cross the Fermi level. Spin-orbit coupling induced maximum splitting ( EASOC/kBTc) of the electronic bands near the Fermi level was found to be 1697, 517, 1138, and 4230 for HfNiAl, ZrNiAl, ZrNiGa, and HfPtAl, respectively. Large variation of the antisymmetric spin-orbit coupling (ASOC) among these compounds provides a great opportunity to study the effects of ASOC on the superconducting pairing states.

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Ternary transition metal gallides with TiNiSi, ZrBeSi and MgZn₂-type structure

Heletta

Block

Klenner

et al. 2019

Zeitschrift Für Naturforschung B

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A series of ternary transition metal gallides around the equiatomic composition have been synthesized from the elements by arc-melting and subsequent annealing. The compounds crystallize with site occupancy variants of the hexagonal Laves phase MgZn2, with the hexagonal ZrBeSi or the orthorhombic TiNiSi type. All samples have been characterized on the basis of their lattice parameters, determined by X-ray powder diffraction (Guinier technique). The structures of NbCr1.58Ga0.42 and NbFe1.51Ga0.49 (MgZn2 type, P63/mmc), NbRhGa (ZrBeSi type, P63/mmc), and ScNiGa, ScPtGa and ScAuGa (TiNiSi type, Pnma) were refined from single crystal X-ray diffractometer data. The ScPtGa and ScAuGa crystals showed trilling formation. Mixed site occupancies were only observed in the Laves phases while all other crystals were well ordered. A striking structural motif of NbRhGa is the formation of niobium chains (264 pm Nb–Nb) along the c axis. Several gallides were magnetically characterized. They are Pauli paramagnets. The two crystallographically independent iron sites in the Laves phase TaFeGa could be distinguished in the 57Fe Mössbauer spectrum. The isomer shifts of 0.06(3) (Fe1) and –0.02(3) (Fe2) mm s−1 indicate metallic iron.

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ZrNiAl-type gallides with pronounced metal-metal bonding, and the dimorphism of ScPdGa

Cited by 3 publications

References 53 publications

Correlations of Crystal and Electronic Structure via NMR and X-ray Photoelectron Spectroscopies in the RETMAl₂(RE = Sc, Y, La–Nd, Sm, Gd–Tm, Lu; TM = Ni, Pd, Pt) Series

Correlations of Crystal and Electronic Structure via NMR and X-ray Photoelectron Spectroscopies in the RETMAl₂(RE = Sc, Y, La–Nd, Sm, Gd–Tm, Lu; TM = Ni, Pd, Pt) Series

Superconductivity in non-centrosymmetric ZrNiAl and HfRhSn-type compounds

Ternary transition metal gallides with TiNiSi, ZrBeSi and MgZn₂-type structure

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ZrNiAl-type gallides with pronounced metal-metal bonding, and the dimorphism of ScPdGa

Cited by 3 publications

References 53 publications

Correlations of Crystal and Electronic Structure via NMR and X-ray Photoelectron Spectroscopies in the RETMAl2(RE = Sc, Y, La–Nd, Sm, Gd–Tm, Lu; TM = Ni, Pd, Pt) Series

Correlations of Crystal and Electronic Structure via NMR and X-ray Photoelectron Spectroscopies in the RETMAl2(RE = Sc, Y, La–Nd, Sm, Gd–Tm, Lu; TM = Ni, Pd, Pt) Series

Superconductivity in non-centrosymmetric ZrNiAl and HfRhSn-type compounds

Ternary transition metal gallides with TiNiSi, ZrBeSi and MgZn2-type structure

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Correlations of Crystal and Electronic Structure via NMR and X-ray Photoelectron Spectroscopies in the RETMAl₂(RE = Sc, Y, La–Nd, Sm, Gd–Tm, Lu; TM = Ni, Pd, Pt) Series

Correlations of Crystal and Electronic Structure via NMR and X-ray Photoelectron Spectroscopies in the RETMAl₂(RE = Sc, Y, La–Nd, Sm, Gd–Tm, Lu; TM = Ni, Pd, Pt) Series

Ternary transition metal gallides with TiNiSi, ZrBeSi and MgZn₂-type structure