The Experts below are selected from a list of 1659 Experts worldwide ranked by ideXlab platform
Liemeng Chen - One of the best experts on this subject based on the ideXlab platform.
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implications of nano and micrometer size platinum group element minerals in base metal sulfides of the yangliuping ni cu pge sulfide deposit sw china
Chemical Geology, 2019Co-Authors: Qinglin Liang, Richard Wirth, Liemeng ChenAbstract:Abstract The concentrations of platinum-group elements (PGE) and semimetal elements (As, Sb, Se, Te and Bi) in the base metal sulfides from the Yangliuping deposit were determined using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS). Mass balance calculation reveals that the base metal sulfides only contain Cu-(PGE) sulfide deposits. Euhedral shape and similar chemical composition of the nanometer-size PGE-Arsenides and sulfArsenides in the base-metal sulfides suggest that they crystallized from the sulfide melt before the crystallization of monosulfide solid solution (MSS) and intermediate solid solution (ISS). It is proposed that the nanometer-size PGE-Arsenides and sulfArsenides formed from PGE-As molecular or polymolecular clusters in the sulfide liquid at high temperature. The PGE-As molecular or polymolecular clusters prevent As and PGE from partitioning into the base metal sulfide lattice and tend to form discrete nanometer-size PGE-Arsenides and sulfArsenides. Thus, semimetal elements, particularly As, play an important role on behaviour of PGE during solidification of magmatic sulfide liquids.
Qinglin Liang - One of the best experts on this subject based on the ideXlab platform.
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implications of nano and micrometer size platinum group element minerals in base metal sulfides of the yangliuping ni cu pge sulfide deposit sw china
Chemical Geology, 2019Co-Authors: Qinglin Liang, Richard Wirth, Liemeng ChenAbstract:Abstract The concentrations of platinum-group elements (PGE) and semimetal elements (As, Sb, Se, Te and Bi) in the base metal sulfides from the Yangliuping deposit were determined using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS). Mass balance calculation reveals that the base metal sulfides only contain Cu-(PGE) sulfide deposits. Euhedral shape and similar chemical composition of the nanometer-size PGE-Arsenides and sulfArsenides in the base-metal sulfides suggest that they crystallized from the sulfide melt before the crystallization of monosulfide solid solution (MSS) and intermediate solid solution (ISS). It is proposed that the nanometer-size PGE-Arsenides and sulfArsenides formed from PGE-As molecular or polymolecular clusters in the sulfide liquid at high temperature. The PGE-As molecular or polymolecular clusters prevent As and PGE from partitioning into the base metal sulfide lattice and tend to form discrete nanometer-size PGE-Arsenides and sulfArsenides. Thus, semimetal elements, particularly As, play an important role on behaviour of PGE during solidification of magmatic sulfide liquids.
Richard Wirth - One of the best experts on this subject based on the ideXlab platform.
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implications of nano and micrometer size platinum group element minerals in base metal sulfides of the yangliuping ni cu pge sulfide deposit sw china
Chemical Geology, 2019Co-Authors: Qinglin Liang, Richard Wirth, Liemeng ChenAbstract:Abstract The concentrations of platinum-group elements (PGE) and semimetal elements (As, Sb, Se, Te and Bi) in the base metal sulfides from the Yangliuping deposit were determined using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS). Mass balance calculation reveals that the base metal sulfides only contain Cu-(PGE) sulfide deposits. Euhedral shape and similar chemical composition of the nanometer-size PGE-Arsenides and sulfArsenides in the base-metal sulfides suggest that they crystallized from the sulfide melt before the crystallization of monosulfide solid solution (MSS) and intermediate solid solution (ISS). It is proposed that the nanometer-size PGE-Arsenides and sulfArsenides formed from PGE-As molecular or polymolecular clusters in the sulfide liquid at high temperature. The PGE-As molecular or polymolecular clusters prevent As and PGE from partitioning into the base metal sulfide lattice and tend to form discrete nanometer-size PGE-Arsenides and sulfArsenides. Thus, semimetal elements, particularly As, play an important role on behaviour of PGE during solidification of magmatic sulfide liquids.
Rainer Pottgen - One of the best experts on this subject based on the ideXlab platform.
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superconductivity and crystal structure of the palladium iron Arsenides ca10 fe1 x pd x as 10pd3as8
Philosophical Magazine, 2013Co-Authors: C Hieke, Rainer Pottgen, J Lippmann, Tobias Sturzer, Gina M Friederichs, Fabian Nitsche, F Winter, Dirk JohrendtAbstract:The palladium–iron–Arsenides Ca10(Fe1− x Pd x As)10(Pd3As8) were synthesized by solid-state methods and characterized by X-ray powder and single crystal diffraction. The triclinic crystal structure (space group P ) is isotypic to the homologue platinum 1038-type superconductors with alternating FeAs4/4- and Pd3As8-layers, each separated by layers of calcium atoms. Iron is tetrahedrally and palladium is planar coordinated by four arsenic atoms. As2-dimers (d As–As ≈ 250 pm) are present in the Pd3As8-layer. Even though each layer itself has a four-fold rotational symmetry, the shifted layer stacking causes the triclinic space group. Resistivity measurements of La-doped samples show the onset of superconductivity at 17 K and zero resistivity below 10 K. The magnetic shielding fraction is about 20 % at 3.5 K. 57Fe-Mossbauer spectra exhibit one absorption line and show no hint to magnetic ordering. The electronic structure is very similar to the known iron–Arsenides with cylinder-like Fermi surfaces and partia...
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synthesis crystal structure and spin density wave anomaly of the iron arsenide fluoride srfeasf
EPL, 2008Co-Authors: Marcus Tegel, S Johansson, V Weis, Inga Schellenberg, Wilfried Hermes, Rainer Pottgen, Dirk JohrendtAbstract:The new quaternary iron arsenide-fluoride SrFeAsF with the tetragonal ZrCuSiAs-type structure was synthesized and the crystal structure was determined by X-ray powder diffraction (P4/nmm, a=399.30(1), c=895.46(1) pm). SrFeAsF undergoes a structural and magnetic phase transition at 175 K, accompanied by strong anomalies in the specific heat, electrical resistance and magnetic susceptibility. In the course of this transition, the space group symmetry changes from tetragonal (P4/nmm) to orthorhombic (Cmme). 57Fe Mossbauer spectroscopy experiments show a single signal at room temperature at an isomer shift of 0.30(1) mm/s and magnetic hyperfine-field splitting below the phase transition temperature. Our results clearly show that SrFeAsF exhibits a spin density wave (SDW) anomaly at 175 K very similar to LaFeAsO, the parent compound of the iron arsenide-oxide superconductors and thus SrFeAsF may serve as a further parent compound for oxygen-free iron arsenide superconductors.
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spin density wave anomaly at 140 k in the ternary iron arsenide bafe 2 as 2
Physical Review B, 2008Co-Authors: Marianne Rotter, Marcus Tegel, Inga Schellenberg, Wilfried Hermes, Dirk Johrendt, Rainer PottgenAbstract:The ternary iron arsenide ${\text{BaFe}}_{2}{\text{As}}_{2}$, with the tetragonal ${\text{ThCr}}_{2}{\text{Si}}_{2}$-type structure, exhibits a spin-density-wave (SDW) anomaly at 140 K, very similar to LaFeAsO, which is the parent compound of the iron arsenide superconductors. ${\text{BaFe}}_{2}{\text{As}}_{2}$ is a poor Pauli-paramagnetic metal and undergoes a structural and magnetic phase transition at 140 K, accompanied by strong anomalies in the specific heat, electrical resistance, and magnetic susceptibility. In the course of this transition, the space-group symmetry changes from tetragonal $(I4/mmm)$ to orthorhombic $(Fmmm)$. $^{57}\text{F}\text{e}$ M\"ossbauer spectroscopy experiments show a single signal at room temperature and full hyperfine field splitting below the phase-transition temperature (5.2 T at 77 K). Our results suggest that ${\text{BaFe}}_{2}{\text{As}}_{2}$ can serve as a parent compound for oxygen-free iron arsenide superconductors.
Dirk Johrendt - One of the best experts on this subject based on the ideXlab platform.
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superconductivity and crystal structure of the palladium iron Arsenides ca10 fe1 x pd x as 10pd3as8
Philosophical Magazine, 2013Co-Authors: C Hieke, Rainer Pottgen, J Lippmann, Tobias Sturzer, Gina M Friederichs, Fabian Nitsche, F Winter, Dirk JohrendtAbstract:The palladium–iron–Arsenides Ca10(Fe1− x Pd x As)10(Pd3As8) were synthesized by solid-state methods and characterized by X-ray powder and single crystal diffraction. The triclinic crystal structure (space group P ) is isotypic to the homologue platinum 1038-type superconductors with alternating FeAs4/4- and Pd3As8-layers, each separated by layers of calcium atoms. Iron is tetrahedrally and palladium is planar coordinated by four arsenic atoms. As2-dimers (d As–As ≈ 250 pm) are present in the Pd3As8-layer. Even though each layer itself has a four-fold rotational symmetry, the shifted layer stacking causes the triclinic space group. Resistivity measurements of La-doped samples show the onset of superconductivity at 17 K and zero resistivity below 10 K. The magnetic shielding fraction is about 20 % at 3.5 K. 57Fe-Mossbauer spectra exhibit one absorption line and show no hint to magnetic ordering. The electronic structure is very similar to the known iron–Arsenides with cylinder-like Fermi surfaces and partia...
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synthesis crystal structure and spin density wave anomaly of the iron arsenide fluoride srfeasf
EPL, 2008Co-Authors: Marcus Tegel, S Johansson, V Weis, Inga Schellenberg, Wilfried Hermes, Rainer Pottgen, Dirk JohrendtAbstract:The new quaternary iron arsenide-fluoride SrFeAsF with the tetragonal ZrCuSiAs-type structure was synthesized and the crystal structure was determined by X-ray powder diffraction (P4/nmm, a=399.30(1), c=895.46(1) pm). SrFeAsF undergoes a structural and magnetic phase transition at 175 K, accompanied by strong anomalies in the specific heat, electrical resistance and magnetic susceptibility. In the course of this transition, the space group symmetry changes from tetragonal (P4/nmm) to orthorhombic (Cmme). 57Fe Mossbauer spectroscopy experiments show a single signal at room temperature at an isomer shift of 0.30(1) mm/s and magnetic hyperfine-field splitting below the phase transition temperature. Our results clearly show that SrFeAsF exhibits a spin density wave (SDW) anomaly at 175 K very similar to LaFeAsO, the parent compound of the iron arsenide-oxide superconductors and thus SrFeAsF may serve as a further parent compound for oxygen-free iron arsenide superconductors.
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synthesis crystal structure and spin density wave anomaly of the iron arsenide fluoride srfeasf
arXiv: Superconductivity, 2008Co-Authors: Marcus Tegel, S Johansson, Inga Schellenberg, Wilfried Hermes, V Weiss, Rainer Poettgen, Dirk JohrendtAbstract:The new quaternary iron arsenide-fluoride SrFeAsF with the tetragonal ZrCuSiAs-type structure was synthesized and the crystal structure was determined by X-ray powder diffraction (P4/nmm, a = 399.30(1), c = 895.46(1) pm). SrFeAsF undergoes a structural and magnetic phase transition at 175 K, accompanied by strong anomalies in the specific heat, electrical resistance and magnetic susceptibility. In the course of this transition, the space group symmetry changes from tetragonal (P4/nmm) to orthorhombic (Cmme). 57Fe Moessbauer spectroscopy experiments show a single signal at room temperature at an isomer shift of 0.30(1) mm/s and magnetic hyperfine-field splitting below the phase transition temperature. Our results clearly show that SrFeAsF exhibits a spin density wave (SDW) anomaly at 175 K very similar to LaFeAsO, the parent compound of the iron arsenide-oxide superconductors and thus SrFeAsF may serve as a further parent compound for oxygen-free iron arsenide superconductors.
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spin density wave anomaly at 140 k in the ternary iron arsenide bafe 2 as 2
Physical Review B, 2008Co-Authors: Marianne Rotter, Marcus Tegel, Inga Schellenberg, Wilfried Hermes, Dirk Johrendt, Rainer PottgenAbstract:The ternary iron arsenide ${\text{BaFe}}_{2}{\text{As}}_{2}$, with the tetragonal ${\text{ThCr}}_{2}{\text{Si}}_{2}$-type structure, exhibits a spin-density-wave (SDW) anomaly at 140 K, very similar to LaFeAsO, which is the parent compound of the iron arsenide superconductors. ${\text{BaFe}}_{2}{\text{As}}_{2}$ is a poor Pauli-paramagnetic metal and undergoes a structural and magnetic phase transition at 140 K, accompanied by strong anomalies in the specific heat, electrical resistance, and magnetic susceptibility. In the course of this transition, the space-group symmetry changes from tetragonal $(I4/mmm)$ to orthorhombic $(Fmmm)$. $^{57}\text{F}\text{e}$ M\"ossbauer spectroscopy experiments show a single signal at room temperature and full hyperfine field splitting below the phase-transition temperature (5.2 T at 77 K). Our results suggest that ${\text{BaFe}}_{2}{\text{As}}_{2}$ can serve as a parent compound for oxygen-free iron arsenide superconductors.