Isomer shift and quadrupole splitting in191Ir and193Ir

Wagner, F. E.; Klöckner, J.; Körner, H. J.; Schaller, H.; Kienle, Paul

doi:10.1016/0370-2693(67)90002-0

Cited by 32 publications

(6 citation statements)

References 4 publications

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“…A small single-line component with an isomer shift IS=-1.94 mm/s, observed in the specimens reduced at relatively low temperatures, can be tentatively ascribed to IrCl 3 , in accordance with the literature data [9]. IrCl3 may be formed as an intermediate thermal decomposition product of the initially deposited [Ir(NH 3 ) 5 C1] + ions.…”

Section: Resultssupporting

confidence: 89%

Mössbauer Analysis of Iridium in Pt-Ir/SiO₂ Catalysts

1987

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The state of iridium in highly disperse~9~imetallic Pt-Ir catalysts supported on amorphous silica was studied by Ir M8ssbauer spectroscopy, after deposition via ion exchange, as well as after calcination, reduction in hydrogen, and on exposure to carbon monoxide.Cyracteristic patterns and relative contributions of adsorbed [Ir(NH 3 ) 5 C1] complexes, IrCl 3 , IrO2 and Pt-Ir alloy particles have been identified.The composition of bimetallic particles indicates a strong tendency for segregation of Pt and Ir.

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Section: Resultssupporting

confidence: 89%

Mössbauer Analysis of Iridium in Pt-Ir/SiO₂ Catalysts

1987

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“…The numerical data of ρ 0 calc values are available in the Supporting Information. All of the plots show a positive correlation between δ exp and ρ 0 calc , which is consistent with the experimental result (Δ⟨ r 2 ⟩ > 0) . The coefficient of determination ( R 2 ) between δ exp and ρ 0 calc increased in the order BP86 < B3LYP < BHandHLYP.…”

Section: Resultssupporting

confidence: 86%

Density Functional Theory Study on the ¹⁹³Ir Mössbauer Spectroscopic Parameters of Vaska’s Complexes and Their Oxidative Adducts

Kaneko

Nakashima

2021

Inorg. Chem.

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In the present study, density functional theory (DFT) calculation was applied to Vaska’s complexes of formula trans-[IrIX(CO)(PPh3)2] and their oxidative adducts with small molecules (YZ) including H2, i.e., trans-[IrIIIClYZ(CO)(PPh3)2], to successfully correlate the electronic states of the complexes with the corresponding 193Ir Mössbauer spectroscopic parameters. After confirming the reproducibility of the DFT methods for elucidating the equilibrium structures and 193Ir Mössbauer isomer shifts of the octahedral Ir complexes, the isomer shifts and quadrupole splitting values of Vaska’s complexes and their oxidative adducts were calculated. A bond critical point analysis revealed that the tendency in the isomer shifts was correlated with the strength of the covalent interaction in the coordination bonds. In an electric field gradient (EFG) analysis of the oxidative adducts, the sign of the principal axis was found to be positive for the complex with YZ = Cl2 and negative for the complex with YZ = H2. This reversal of the sign of the EFG principal axis was caused by the difference in the electron density distribution for the coordination bonds between Ir and YZ, according to a density of states analysis.

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“…The increased value of the isomer shift 6 for those atoms in the irradiated sample which feel the vicinity of defects as found in the two-system fit indicates a reduction in the electron density a t the Ir nuclei, since with A(rz) the difference of the squares of the nuclear radii in the ground state and in the excited state of WS3 (O(r2) = +0.006 fm2 [28]) and ea(0), es(0) the electron densities of the Ir nuclei in absorber and source, respectively. The electron density reduction is in agreement with the picture of neighbouring vacancies.…”

Section: Analysis Of Rmpevimental Resultsmentioning

confidence: 74%

Mössbauer studies of low‐temperature radiation damage in α‐iron

Vogl

Schaefer

Mansel

et al. 1973

Physica Status Solidi (b)

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The Mossbauer effect has been used t o study radiation damage in a-iron, doped with 0.6 at?: 0 s and 4 atyo Pt. The samples were irradiated in a nuclear reactor at 4.6 K. The Mossbauer nuclei of Irlg3 and Ada7 were produced by capture of thermal neutrons in OslS2 or Pt196, a process which simultaneously could lead t o radiation damage. Compared with annealed samples, the average magnetic field was reduced after the irradiation by about 2% and the line width was increased by approximately 30%. Isochronal annealing processes were studied. The annealing of the irradiation effects took place primarily between 90 and 140 K with activation energies in the range between 0.30 and 0.40 eV. These effects are interpreted as mainly due to a vacancy as nearest or next nearest neighbour of the displaced Mossbauer atom combined with an interstitial several lattice sites away from the vacancy. The Mossbauer atom does not come to rest as an interstitial atom. These results are in good agreement with results from computer experiments of Vineyard's group. Mit dem MoBbauereffekt wurde die Strahlenschadigung in a-

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Isomer shift and quadrupole splitting in191Ir and193Ir

Cited by 32 publications

References 4 publications

Mössbauer Analysis of Iridium in Pt-Ir/SiO₂ Catalysts

Mössbauer Analysis of Iridium in Pt-Ir/SiO₂ Catalysts

Density Functional Theory Study on the ¹⁹³Ir Mössbauer Spectroscopic Parameters of Vaska’s Complexes and Their Oxidative Adducts

Mössbauer studies of low‐temperature radiation damage in α‐iron

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Isomer shift and quadrupole splitting in191Ir and193Ir

Cited by 32 publications

References 4 publications

Mössbauer Analysis of Iridium in Pt-Ir/SiO2 Catalysts

Mössbauer Analysis of Iridium in Pt-Ir/SiO2 Catalysts

Density Functional Theory Study on the 193Ir Mössbauer Spectroscopic Parameters of Vaska’s Complexes and Their Oxidative Adducts

Mössbauer studies of low‐temperature radiation damage in α‐iron

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Mössbauer Analysis of Iridium in Pt-Ir/SiO₂ Catalysts

Mössbauer Analysis of Iridium in Pt-Ir/SiO₂ Catalysts

Density Functional Theory Study on the ¹⁹³Ir Mössbauer Spectroscopic Parameters of Vaska’s Complexes and Their Oxidative Adducts