Methods of synthesis of iron(II) complexes containing cluster
closo
-borate anions—Fe(Htrz)
3
B
10
Cl
10
(
I
) (HTrz is 1,2,4-triazole), Fe(NH
2
Trz)
3
B
10
Cl
10
· 2H
2
O (
II
) (NH
2
Trz is ...4-amino-1,2,4-triazole), Fe{HC(pz)
3
}
2
B
10
Cl
10
(
III
), Fe{HC(pz)
3
}
2
B
10
H
10
(
IV
), and Fe{HC(pz)
3
}
2
B
12
H
12
· 2H
2
O (
V
) (HC(pz)
3
is tris(pyrazol-1-yl)methane)—have been developed. The compounds have been studied by the static magnetic susceptibility method (78–500 K) and electronic, IR, and EXAFS spectroscopy. Complexes
I
and
II
in the temperature range under consideration remain in the high-spin state. Low-spin complex
III
shows incomplete spin crossover and decomposes on heating above 440 K. Complexes
IV
and
V
are characterized by reversible spin crossover
1
A
1
⇔
5
T
2
accompanied by thermochromism (the pink ⇔ white color change). The crossover temperature (
T
c
) for
IV
and
V
is 375 and 405 K, respectively.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
New iron(II) complexes with 2,6-bis(benzimidazol-2-yl)pyridine (L) and
closo
-borate(2–) anions—FeL
2
B
10
H
10
⋅ 2H
2
O and FeL
2
B
12
H
12
⋅ H
2
O—have been synthesized. The complexes have been ...characterized by static magnetic susceptibility measurements, electronic (diffuse reflectance spectra), IR, and EXAFS spectroscopy, and X-ray diffraction analysis. A study of the μ
eff
(
T
) dependence in the temperature range 80–500 K has shown that the complexes exhibit a high-temperature spin crossover
1
А
1
⇔
5
Т
2
.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Multilayered samples with extremely narrow GaN quantum wells in an AlN host are synthesized via ammonia MBE. The parameters of the microstructure are determined by means of EXAFS spectroscopy, ...high-resolution electron microscopy, and low-angle scattering. Their relationship to the morphology of GaN/AlN superlattices is established. The influence of growth conditions and the thickness of superlattices on their optical properties and mixing in the near-boundary layers is established.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), and EXAFS spectroscopy are used to study the composition and structure of SiC
x
N
y
:Fe films obtained by chemical vapor ...deposition (CVD) in the Fe–Si–C–N–H system from a mixture of hydrogen, ferrocene (C
5
H
5
)
2
Fe, and organosilicon compound 1,1,3,3,5,5–hexamethylcyclotrisilazane (HMCTS) C
6
H
21
N
3
Si
3
. The films are deposited under low pressures (LPCVD) at 1123–1273 K, and their phase composition at 300–1300 K is predicted using thermodynamic modeling. The obtained films are nanocomposites with amorphous matrices containing α-Fe crystallites and carbon clusters with a size of 5–10 nm.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The microstructures of amorphous and polycrystalline ferroelectric Hf{sub 0.5}Zr{sub 0.5}O{sub 2} films are studied by X-ray spectroscopy and ellipsometry. EXAFS spectra demonstrate that the ...amorphous film consists of an “incompletely mixed” solid solution of metallic oxides HfO{sub 2} and ZrO{sub 2}. After rapid thermal annealing, the mixed Hf{sub 0.5}Zr{sub 0.5}O{sub 2} oxide films have a more ordered polycrystalline structure, and individual Hf and Zr monoxide islands are formed in the films. These islands are several nanometers in size and have a structure that is similar to the monoclinic structure of HfO{sub 2} and ZrO{sub 2}. The presence of the HfO{sub 2} and ZrO{sub 2} phases in the Hf{sub 0.5}Zr{sub 0.5}O{sub 2} films is also detected by ellipsometry.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The microstructures of amorphous and polycrystalline ferroelectric Hf.sub.0.5Zr.sub.0.5O.sub.2 films are studied by X-ray spectroscopy and ellipsometry. EXAFS spectra demonstrate that the amorphous ...film consists of an "incompletely mixed" solid solution of metallic oxides HfO.sub.2 and ZrO.sub.2. After rapid thermal annealing, the mixed Hf.sub.0.5Zr.sub.0.5O.sub.2 oxide films have a more ordered polycrystalline structure, and individual Hf and Zr monoxide islands are formed in the films. These islands are several nanometers in size and have a structure that is similar to the monoclinic structure of HfO.sub.2 and ZrO.sub.2. The presence of the HfO.sub.2 and ZrO.sub.2 phases in the Hf.sub.0.5Zr.sub.0.5O.sub.2 films is also detected by ellipsometry.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), and EXAFS spectroscopy are used to study the composition and structure of SiCxNy:Fe films obtained by chemical vapor ...deposition (CVD) in the Fe–Si–C–N–H system from a mixture of hydrogen, ferrocene (C5H5)2Fe, and organosilicon compound 1,1,3,3,5,5–hexamethylcyclotrisilazane (HMCTS) C6H21N3Si3. The films are deposited under low pressures (LPCVD) at 1123–1273 K, and their phase composition at 300–1300 K is predicted using thermodynamic modeling. The obtained films are nanocomposites with amorphous matrices containing α-Fe crystallites and carbon clusters with a size of 5–10 nm.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Novel iron(II) coordination compounds containing a ligand 2,6-bis(1H-imidazol-2-yl)pyridine (L), having such a composition as FeL2SO4·0.5H2O, FeL2Br2·H2O, FeL2(ReO4)2, FeL2B10H10∙H2O, ...FeL2B12H12∙1.5H2O had been synthesized and studied using UV-Vis (diffuse reflectance), infrared, extended X-ray absorption fine structure (EXAFS), and Mössbauer spectroscopy methods, as well as X-ray diffraction and static magnetic susceptibility methods. The analysis of the μeff(T) dependence in the temperature range of 80–600 K have shown that all the obtained complexes exhibit a high-temperature spin crossover 1A1 ↔ 5T2.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We investigate the microstructure of Ge/Si and GaN/AlN sandwiches containing vertically aligned QDs. The study establishes an influence of blocking layers (Si, AlN) thickness, number of QDs layers ...(Ge, GaN) in heterostructure and annealing temperature on the microstructure characteristics of systems with quantum dots.
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