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1.
When Eu2(SO3)3·3H2O is heated in air it forms after dehydration two sulfite-sulfate phases: Eu2(SO3)2SO2 and Eu2SO3(SO4)2. The latter phase is thermally remarkably stable and decomposes above 700°C via Eu2O2SO4 to Eu2O3. Anhydrous Eu2(SO3)3 and Eu2O2SO4 were also found as intermediates before Eu2O3 when the TG experiments were carried out in nitrogen but in other details the decomposition mechanism differs from that in air.
For Part VII, see ref. 6. 相似文献
Zusammenfassung Eu2(SO3)3·3H2O bildet durch Erhitzen in Luft nach Dehydratation zwei Sulfit-Sulfat-Phasen: Eu2(SO3)2SO4 und Eu2SO3(SO4)2·Letztere ist thermisch bedeutend stabiler und zersetzt sich oberhalb 700°C über Eu2O2SO4 zu Eu2O3. Bei Durchführung der TG-Experimente in Stickstoff wurden als Zwischenprodukte vor Eu2O3 auch wasserfreies Eu2(SO3)3 und Eu2O2SO4 gefunden, in anderen Details weicht jedoch der Mechanismus der Zersetzung von dem der Zersetzung in Luft ab.
- Eu/SO3/2SO4 Eu2SO3/SO4/2. 700° Eu2O3 Eu2O2SO4. Eu2/SO3/3 Eu2O2SO4 , .
For Part VII, see ref. 6. 相似文献
2.
M. Karppinen Y. Morita I. Grigoraviciute R.S. Liu 《Journal of solid state chemistry》2005,178(11):3464-3470
Superconductivity characteristics have been systematically evaluated for a two-CuO2-plane copper oxide system, (Cu,Mo)-12s2, upon increasing the number of fluorite-structured layers, s, between the two CuO2 planes. Essentially single-phase samples of (Cu0.75Mo0.25)Sr2YCu2O7+δ (s=1), (Cu0.75Mo0.25)Sr2(Ce0.45Y0.55)2Cu2O9+δ (s=2) and (Cu0.75Mo0.25)Sr2(Ce0.67Y0.33)3Cu2O11+δ (s=3) were synthesized through a conventional solid-state route in air. To make the samples superconductive an additional high-pressure oxygenation (HPO) treatment was required. Such treatment (carried out at 5 GPa and 500 °C in the presence of 75 mol% Ag2O2 as an oxygen source to maximize the Tc) compressed the crystal lattice for the three members of the (Cu0.75Mo0.25)-12s2 series equally, i.e., by 0.01 Å for the a parameter and by 0.07 Å for the c parameter per formula unit. From both Cu L-edge and O K-edge XANES spectra the s=1 sample was found to possess the highest overall hole-doping level among the HPO samples. Accordingly it exhibited the best superconductivity characteristics. With increasing s, both the Tc (s=1: 88 K, s=2: 61 K, s=3: 53 K) and Hirr values got depressed, being well explained by the trend of decreasing CuO2-plane hole concentration with increasing s as revealed from O K-edge XANES spectra for the same samples. Hence, the present results do not suggest any significant (negative) impact on the superconductivity characteristics from the gradually thickened fluorite-structured block itself. 相似文献
3.
Analysing the general dispersion relation numerically, the unstable regions of the relativistic electron-beam plasma system were determined. The external parameters were varied to ensure more effective instability excitations. The full charge and current compensation presumptions lead to new synchronism predictions. The return current's slow space charge wave and return current's slow cyclotron wave are synchronous with the plasma ion wave. 相似文献
4.
5.
Petr Tůma Martin Jaček Blanka Sommerová Pavel Dlouhý Radka Jarošíková Jitka Husáková Veronika Wosková Vladimíra Fejfarová 《Electrophoresis》2022,43(11):1129-1139
Determination of the broad-spectrum antibiotics amoxicilline (AMX) and ceftazidime (CTZ) in blood serum and microdialysates of the subcutaneous tissue of the lower limbs is performed using CE with contactless conductivity detection (C4D). Baseline separation of AMX is achieved in 0.5 M acetic acid as the background electrolyte and separation of CTZ in 3.2 M acetic acid with addition of 13% v/v methanol. The CE-C4D determination is performed in a 25 µm capillary with suppression of the EOF using INST-coating on an effective length of 18 cm and the attained migration time is 4.2 min for AMX and 4.4 min for CTZ. The analysis was performed using 20 µl of serum and 15 µl of microdialysate, treated by the addition of acetonitrile in a ratio of 1/3 v/v and the sample is injected into the capillary using the large volume sample stacking technique. The LOQ attained in the microdialysate is 148 ng/ml for AMX and 339 ng/ml for CTZ, and in serum 143 ng/ml for AMX and 318 ng/ml for CTZ. The CE-C4D method is employed for monitoring the passage of AMX and CTZ from the blood circulatory system into the subcutaneous tissue at the sites of diabetic ulceration in patients suffering from diabetic foot syndrome and also for measuring the pharmacokinetics following intravenous application of bolus antibiotic doses. 相似文献
6.
Parmish Kaur Lukas Mai Arbresha Muriqi David Zanders Ramin Ghiyasi Dr. Muhammad Safdar Nils Boysen Manuela Winter Prof. Michael Nolan Prof. Maarit Karppinen Prof. Anjana Devi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(15):4913-4926
Owing to the limited availability of suitable precursors for vapor phase deposition of rare-earth containing thin-film materials, new or improved precursors are sought after. In this study, we explored new precursors for atomic layer deposition (ALD) of cerium (Ce) and ytterbium (Yb) containing thin films. A series of homoleptic tris-guanidinate and tris-amidinate complexes of cerium (Ce) and ytterbium (Yb) were synthesized and thoroughly characterized. The C-substituents on the N-C-N backbone (Me, NMe2, NEt2, where Me=methyl, Et=ethyl) and the N-substituents from symmetrical iso-propyl (iPr) to asymmetrical tertiary-butyl (tBu) and Et were systematically varied to study the influence of the substituents on the physicochemical properties of the resulting compounds. Single crystal structures of [Ce(dpdmg)3] 1 and [Yb(dpdmg)3] 6 (dpdmg=N,N'-diisopropyl-2-dimethylamido-guanidinate) highlight a monomeric nature in the solid-state with a distorted trigonal prismatic geometry. The thermogravimetric analysis shows that the complexes are volatile and emphasize that increasing asymmetry in the complexes lowers their melting points while reducing their thermal stability. Density functional theory (DFT) was used to study the reactivity of amidinates and guanidinates of Ce and Yb complexes towards oxygen (O2) and water (H2O). Signified by the DFT calculations, the guanidinates show an increased reactivity toward water compared to the amidinate complexes. Furthermore, the Ce complexes are more reactive compared to the Yb complexes, indicating even a reactivity towards oxygen potentially exploitable for ALD purposes. As a representative precursor, the highly reactive [Ce(dpdmg)3] 1 was used for proof-of-principle ALD depositions of CeO2 thin films using water as co-reactant. The self-limited ALD growth process could be confirmed at 160 °C with polycrystalline cubic CeO2 films formed on Si(100) substrates. This study confirms that moving towards nitrogen-coordinated rare-earth complexes bearing the guanidinate and amidinate ligands can indeed be very appealing in terms of new precursors for ALD of rare earth based materials. 相似文献
7.
I. Tittonen J. Hietaniemi J. Huttunen T. Karlemo M. Karppinen T. Katila J. Lindén L. Niinistö K. Ullakko 《Hyperfine Interactions》1990,55(1-4):1405-1409
The influence of sintering temperatures and nominal starting compositions on the phase contents of polycrystalline Bi2Sr2Ca n-1Cu n O4+2n samples are reported. After every sintering the samples were characterized with X-ray diffraction and magnetic AC susceptibility measurements. For Mössbauer studies, in each case also a corresponding specimen containing57Fe was synthetized. The identification of various superconducting Bi2Sr2Ca n-1Cu n O4+2n phases on the basis of Mössbauer spectra consisting usually of three quadrupole doublets is discussed. 相似文献
8.
S. Vasala Y.H. Huang H. Yamauchi M. Karppinen 《Journal of solid state chemistry》2010,183(5):1007-1012
We have investigated a series of double-perovskite oxides Sr2MMoO6−δ (M=Mg, Mn, Fe, Co, Ni, Zn) for redox stability, oxygen content and crystal structure. Phases with M=Co, Ni and Zn were found to be oxygen-stoichiometric and stable under oxidizing conditions, whereas those with M=Mn and Fe were oxygen-deficient and stable under reducing conditions. The M=Mg phase is stable both under reducing and oxidizing conditions, showing variable oxygen contents within 0.00≤δ≤0.04 depending on the annealing conditions. Structural data indicate somewhat depressed values for the degree of M/Mo cation order and also evidence of electron transfer from MII to MoVI for M=Mn, Fe and Co. 相似文献
9.
Differential scanning calorimetry (DSC) is one of the most frequently used techniques for analyzing small concentrations of
amorphous phases in a crystalline matrix. In recent years novel enhanced DSC approaches have been intensively looked for to
improve parameters such as sensitivity, accuracy, and detection limit of the technique. Low levels of amorphous phases can
be quantitatively determined in DSC by measuring the heat capacity change associated with the glass transition. In this short
review the potentials provided by the HyperDSC and StepScan DSC techniques are discussed. Examples illustrate the advantages
and disadvantages of the techniques and compare their abilities to detect small glass transitions and determine low contents
of amorphous phases in samples which are mostly crystalline. 相似文献
10.
This paper presents a system that accurately measures the distance travelled by ultrasound waves through the air. The simple design of the system and its obtained accuracy provide a tool for non-contact distance measurements required in the laser’s optical system that investigates the surface of the eyeball. 相似文献