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

Author(s):  
I. N. Ivleva ◽  
Yu. M. Shul'ga ◽  
O. V. Krylov ◽  
V. A. Matyshak ◽  
Yu. G. Borod'ko
Author(s):  
Irina E. Vasilyeva ◽  
Sergey V. Nekipelov ◽  
Boris A. Makeev ◽  
Alexey G. Krasnov ◽  
Nadezhda A. Zhuk

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


Author(s):  
Nadezhda A. Zhuk ◽  
Lubov V. Rychkova ◽  
Sergey V. Nekipelov ◽  
Boris A. Makeev

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


Author(s):  
Lubov V. Rychkova ◽  
Sergey V. Nekipelov ◽  
Boris A. Makeev ◽  
Vladimir A. Belyy ◽  
Dmitriy S. Beznosikov ◽  
...  

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.


1973 ◽  
Vol 51 (3) ◽  
pp. 438-447 ◽  
Author(s):  
R. Makhija ◽  
L. Pazdernik ◽  
R. Rivest

A new series of octahedral cobalt(II) complexes are formed when CoX2(X = Cl, Br, I, SCN) reacts with Hg(SCN)2 in the presence of Lewis bases. These complexes of stoichiometry CoHg(SCN)4•2L (L = THF, dioxane, pyridine, aniline) are pink to violet solids which slowly decompose to the blue crystalline solid, CoHg(SCN)4, the stable magnetic susceptibility standard. On further reaction of CoHg(SCN)4•2THF with mono-, bi-, and polydentate ligands in dry ethanol, complexes of the following types are obtained: CoHg(SCN)4•2L (L = PΦ3), CoHg(SCN)4•2LL (LL = trien), CoHg(SCN)4•3LL (LL = en, bipy), and CoHg(SCN)4•4LL (LL = phen). The stoichiometry of these were determined by elemental analysis. Possible structures of these are discussed with the help of mid and far infrared, visible, and ultraviolet spectroscopy, magnetic susceptibility, and X-ray powder diffraction. Some new i.r. bands like Co—P, Co—N, and Hg—S are assigned in the low region.


Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 640
Author(s):  
Hideaki Sasaki ◽  
Keisuke Sakamoto ◽  
Masami Mori ◽  
Tatsuaki Sakamoto

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.


2013 ◽  
Vol 68 (9) ◽  
pp. 971-978 ◽  
Author(s):  
Inga Schellenberg ◽  
Ute Ch. Rodewald ◽  
Christian Schwickert ◽  
Matthias Eul ◽  
Rainer Pöttgen

The ternary antimonides RE4T7Sb6 (RE=Gd-Lu; T =Ru, Rh) have been synthesized from the elements by arc-melting and subsequent annealing in an induction furnace. The samples have been characterized by powder X-ray diffraction. Four structures were refined on the basis of single-crystal X-ray diffractometer data: U4Re7Si6 type, space group Im3m with a=862.9(2) pm, wR2=0.0296, 163 F2 values for Er4Ru7Sb6; a=864.1(1) pm, wR2=0.1423, 153 F2 values for Yb4Ru7Sb6; a=872.0(2) pm, wR2=0.0427, 172 F2 values for Tb4Rh7Sb6; and a=868.0(2) pm, wR2=0.0529, 154 F2 values for Er4Rh7Sb6, with 10 variables per refinement. The structures have T1@Sb6 octahedra and slightly distorted RE@T26Sb6 cuboctahedra as building units. The distorted cuboctahedra are condensed via all trapezoidal faces, and this network leaves octahedral voids for the T1 atoms. The ruthenium-based series of compounds was studied by temperature-dependent magnetic susceptibility measurements. Lu4Ru7Sb6 is Pauli-paramagnetic. The antimonides RE4Ru7Sb6 with RE=Dy, Ho, Er, and Tm show Curie-Weiss paramagnetism. Antiferromagnetic ordering occurs at 10.0(5), 5.1(5) and 4.0(5) K for Dy4Ru7Sb6, Ho4Ru7Sb6 and Er4Ru7Sb6, respectively, while Tm4Ru7Sb6 remains paramagnetic. Yb4Ru7Sb6 is an intermediate-valent compound with a reduced magnetic moment of 3.71(1) μB per Yb as compared to 4.54 μB for a free Yb3+ ion


1998 ◽  
Vol 266 (1-2) ◽  
pp. 230-233 ◽  
Author(s):  
S. Danilkin ◽  
H. Fuess ◽  
E. Jadrowski ◽  
T. Wieder ◽  
H. Wipf

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