scholarly journals NEXAFS–Spectra and Magnetic Susceptibility of Nickel and Chromium Doped of Bismuth Niobate

2020 ◽  
pp. 340-348
Author(s):  
Irina E. Vasilyeva ◽  
Sergey V. Nekipelov ◽  
Boris A. Makeev ◽  
Alexey G. Krasnov ◽  
Nadezhda A. Zhuk
Keyword(s):  
Magnetic Susceptibility ◽  
Charge State ◽  
Electronic State ◽  
High Spin ◽  
Solid Solutions ◽  
Exchange Interactions ◽  
High Spin State ◽  
Chromium Oxides ◽  
X Ray ◽  
Nexafs Spectroscopy

The electronic state and character of exchange interactions of nickel and chromium atoms in solid solutions of Bi5Nb3-3xМ3xO15-δ (М-Cr,Ni) was researched by methods of magnetic susceptibility and NEXAFS-spectroscopy. NEXAFS spectra of nickel and chromium oxides were obtained. According to X-ray spectroscopy in solid solutions, chromium atoms are mainly in the charge state of Cr(III), and nickel atoms in the high-spin state of Ni(II) in octahedral coordination. In solid solutions, paramagnetic chromium and nickel atoms are present in the form of monomers and clusters with a common antiferromagnetic type of exchange

scholarly journals Phase Transformations, Magnetic Susceptibility and NEXAFS-Spectra of Cobalt-Doped Solid Solutions of Bismuth Orthoniobate

2020 ◽  
pp. 89-98
Author(s):  
Nadezhda A. Zhuk ◽  
Lubov V. Rychkova ◽  
Sergey V. Nekipelov ◽  
Boris A. Makeev
Keyword(s):  
Magnetic Susceptibility ◽  
Phase Transformation ◽  
Phase Transformations ◽  
Electronic State ◽  
Solid Solutions ◽  
Electron State ◽  
Exchange Interactions ◽  
X Ray ◽  
Nexafs Spectroscopy ◽  
Charge States

The electron state and the nature of the exchange interactions of cobalt atoms in BiNb1-xСoxO4-δ solid solutions of triclinic and orthorhombic modifications were studied using the magnetic susceptibility and NEXAFS-spectroscopy. In order to determine the electronic state of cobalt atoms, the solid solutions and oxides of cobalt CoO, Co3O4 were studied by NEXAFS-spectroscopy. The X-ray spectroscopy and the study of the magnetic susceptibility of the solid solutions revealed the presence of the monomers and exchange-related clusters of cobalt with the Co(II) and Co(III) charge states characterized mostly by the antiferromagnetic type of exchange. The cobalt containing solid solutions allowed us to confirm the reversibility of the α↔β-BiNbO4 phase transformation

scholarly journals Magnetic Behavior and Nexafs-spectroscopy of Bi₂BaNb₂₋₂ₓСo₂ₓO₉₋δ

2019 ◽  
pp. 687-693 ◽  
Author(s):  
Lubov V. Rychkova ◽  
Sergey V. Nekipelov ◽  
Boris A. Makeev ◽  
Vladimir A. Belyy ◽  
Dmitriy S. Beznosikov ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Solid Solutions ◽  
Electron State ◽  
Solid Phase ◽  
Exchange Interactions ◽  
Magnetic Behavior ◽  
Phase Method ◽  
X Ray ◽  
Nexafs Spectroscopy ◽  
Solid Phase Method

The samples of solid solutions of Bi₂BaNb₂₋₂ₓСo₂ₓO₉₋δ composition at x 0:04 were synthesized by the solid-phase method. The electron state and the nature of the exchange interactions of cobalt atoms in the samples were studied by the measurements of magnetic susceptibility and NEXAFS-spectroscopy. The NEXAFS spectra of the solid solutions and the cobalt oxides CoO, Co3O4 were recorded. According to the data of X-ray spectroscopy and magnetic susceptibility, the charge states of cobalt atoms in the solid solutions were identified as Co(II) and Co(III) in the forms of monomers and exchange-bound aggregates with the antiferromagnetic type of exchange.

scholarly journals Thermal trapped iron(II) high spin state investigated by X-ray diffraction

2004 ◽  
Vol 65 (1) ◽  
pp. 17-23 ◽  
Author(s):  
M. Marchivie ◽  
P. Guionneau ◽  
J.F. Létard ◽  
D. Chasseau ◽  
J.A.K. Howard
Keyword(s):  
High Spin ◽  
Spin State ◽  
High Spin State ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Magnetic behavior of Fe-doped of multicomponent bismuth niobate pyrochlore

2021 ◽  
Vol 60 (1) ◽  
pp. 38-46
Author(s):  
Nadezhda A. Zhuk ◽  
Boris A. Makeev ◽  
Sergey V. Nekipelov ◽  
Maria V. Yermolina ◽  
Anna V. Fedorova ◽  
...  
Keyword(s):  
Solid Solutions ◽  
Solid Phase ◽  
Synthesis Method ◽  
Pyrochlore Structure ◽  
Exchange Interactions ◽  
Magnetic Behavior ◽  
Susceptibility Data ◽  
Nexafs Spectroscopy ◽  
Magnetic Dilution ◽  
Paramagnetic Atoms

Abstract Two series of iron-containing solid solutions Bi2Mg1− x Fe x Nb2O9+δ and Bi2MgNb2−2 x Fe2 x O9−δ of pyrochlore structure were obtained by the traditional solid phase synthesis method. The electronic state and character of exchange interactions of iron atoms in solid solutions were investigated by methods of magnetic dilution and NEXAFS-spectroscopy. According to X-ray spectroscopy and magnetic susceptibility data, iron(III) atoms are distributed mainly in octahedral positions of niobium(V) and in a dominant amount are in the charge state of Fe(III) in the form of monomers and exchange-bonded clusters mainly with antiferromagnetic type of exchange. Differences in magnetic behavior of iron-containing solid solutions of both series have been revealed. Antiferromagnetic and ferromagnetic exchange can be realized between iron atoms, which, with increasing concentration of paramagnetic atoms and averaging structure distortions, becomes less significant. The parameters of exchange interactions in clusters and distribution of iron paramagnetic atoms depending on the concentration of solid solutions have been calculated.

scholarly journals The Electronic Structure Signature of the Spin Cross-Over Transition of [Co(dpzca)2]

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Xin Zhang ◽  
Sai Mu ◽  
Yang Liu ◽  
Jian Luo ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Electronic Structure ◽  
Temperature Dependence ◽  
Absorption Spectroscopy ◽  
Spin State ◽  
Density Functional ◽  
Correlation Energy ◽  
High Spin State ◽  
X Ray ◽  
X Ray Absorption

Abstract The unoccupied electronic structure of the spin crossover molecule cobalt (II) N-(2-pyrazylcarbonyl)-2-pyrazinecarboxamide, [Co(dpzca)2] was investigated, using X-ray absorption spectroscopy (XAS) and compared with magnetometry (SQUID) measurements. The temperature dependence of the XAS and molecular magnetic susceptibility χmT are in general agreement for [Co(dpzca)2], and consistent with density functional theory (DFT). This agreement of magnetic susceptibility and X-ray absorption spectroscopy provides strong evidence that the changes in magnetic moment can be ascribed to changes in electronic structure. Calculations show the choice of Coulomb correlation energy U has a profound effect on the electronic structure of the low spin state, but has little influence on the electronic structure of the high spin state. In the temperature dependence of the XAS, there is also evidence of an X-ray induced excited state trapping for [Co(dpzca)2] at 15 K.

scholarly journals Spectral studies of bismuth-containing pyrochlores

2021 ◽  
Vol 2103 (1) ◽  
pp. 012146
Author(s):  
S V Nekipelov ◽  
N A Zhuk ◽  
O V Petrova ◽  
D V Sivkov ◽  
K A Bakina ◽  
...  
Keyword(s):  
Charge State ◽  
Solid Solutions ◽  
Pyrochlore Structure ◽  
Spectral Studies ◽  
Nexafs Spectroscopy ◽  
Cobalt Nickel ◽  
Metal Atoms ◽  
Thermal Stable

Abstract Thermal stable solid solutions of titanates, niobates, and tantalates of bismuth with a pyrochlore structure doped with 3d-metal atoms were studied using XPS and NEXAFS spectroscopy. Based on spectral studies, it was shown that the manganese, cobalt, nickel and copper atoms in these solid solutions have mainly charge state +2 and iron atoms – charge state +3.

Magnetic susceptibility and x-ray photoelectronic spectra of CoO-MgO solid solutions

1977 ◽  
Vol 26 (4) ◽  
pp. 832-833
Author(s):  
I. N. Ivleva ◽  
Yu. M. Shul'ga ◽  
O. V. Krylov ◽  
V. A. Matyshak ◽  
Yu. G. Borod'ko
Keyword(s):  
Magnetic Susceptibility ◽  
Solid Solutions ◽  
X Ray
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