scholarly journals Characterization of Quaternary Metal Oxide Films by Synchrotron X-ray Fluorescence Microprobe

1997 ◽  
Vol 51 (12) ◽  
pp. 1781-1783 ◽  
Author(s):  
D. L. Perry ◽  
A. C. Thompson ◽  
R. E. Russo ◽  
X. L. Mao ◽  
K. L. Chapman

A synchrotron X-ray fluorescence microprobe has been used to study the composition and microstructure of pulsed-laser ablation-deposited films of calcium–nickel–potassium oxides that have applications in heterogeneous catalysis. The films, whose individual metal oxide components have widely varying boiling points and thus prevent a solid-phase synthesis with the use of standard thermal techniques, represent a new quaternary metal oxide phase containing the three elements. Experimental conditions for preparing the films are given. The X-ray fluorescence microprobe data are discussed with respect to both the distribution of the three metals in the films at the micrometer lateral spatial resolution level and the presence of trace amounts of metals that were introduced into the films as contaminants in targets made of the parent three-metal oxide.

1998 ◽  
Vol 524 ◽  
Author(s):  
R. Ravikumar ◽  
D. W. Fuerstenau ◽  
G. A. Waychunas

ABSTRACTUsing silver K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy, two different samples of silver-containing manganese oxide were analyzed in the fluorescence mode. For the first sample, silver ions from solution were sorbed onto one synthetic manganese oxide phase, namely cryptomelane (KxMn8O16, where l<x<2). The second sample was a silvermanganese oxide from Colorado. From the EXAFS analysis, silver was found to occupy two different sites in the synthetic sample. The natural samples from Colorado also exhibited a very similar coordination distances as the synthetic samples. In the low temperature spectrum of the synthetic sample at 10 K, the Ag-O peak was found to be missing and the amplitude of the Ag- Ag peak was approximately three times larger than the corresponding room temperature sample.


2007 ◽  
Vol 95 (8) ◽  
Author(s):  
Cynthia-May S. Gong ◽  
Frédéric Poineau ◽  
Kenneth R. Czerwinski

A novel dry synthesis for the uranium(VI) dioxo-diacetohydroxamate (UAHA) complex has been developed. The complex was generated in >80% yield by mechanically grinding solid uranyl acetate dihydrate (UAc) with solid acetohydroxamic acid in stoichiometric amounts. The resulting UOThe UAHA solid was extensively characterized by ultraviolet-visible (UV-vis), Fourier-transform infrared (FT-IR), and extended X-ray absorption fine structure (EXAFS) spectroscopies. The compound did not fluoresce after laser excitation. Proton nuclear magnetic resonance (NMR) spectra were obtained of the complex in DThe easy synthesis and purification of UAHA enables researchers to strictly control reaction conditions; to eliminate interfering salts and water; and to study the complex in the solid-phase.


2005 ◽  
Vol 19 (03) ◽  
pp. 85-98 ◽  
Author(s):  
S. BELLUCCI

One of the main involvements of the INFN-Laboratori Nazionali di Frascati group in channeling researches is described, i.e. the crystal undulator R & D, with the characterization of the crystal undulator prototypes with SEM and the positron beam. We consider a precise determination of the optimal experimental conditions for channeling of this kind of accelerated particles through such microstructured crystals, as promising candidates for producing X-ray beams.


1988 ◽  
Vol 126 ◽  
Author(s):  
John F. Knudsen ◽  
R. C. Bowman ◽  
P. M. Adams ◽  
R. Newman ◽  
J. P. Hurrell ◽  
...  

ABSTRACTEpitaxial regrowth of deposited amorphous silicon has been previously described utilizing ion implantation amorphization, ion mixing and thermal anneal. This paper evaluates the effects of these process steps on crystalline quality utilizing Rutherford Backscattering (RBS), x-ray diffraction rocking curves and Raman scattering.In situ (during implantation) regrowth results in defective crystallinity. In contrast, when there is no in situ regrowth, the post anneal crystallinity is equivalent by RBS and x-ray evaluation to virgin single crystal wafers. In situ regrowth is most pronounced during the high beam current ion mixing type implants which produce wafer temperatures of about 250°C. The final crystalline quality which results from different sequences of amorphization and ion mixing implants, is strongly dependent upon the amount of in situ regrowth which has occurred. The greater the in situ regrowth the poorer the final crystalline quality.


Author(s):  
Muhkametkali Mataev ◽  
Moldir Abdraimova ◽  
A. Atabay

The complex oxide phase of the composition YbBiNaFe2O6,5 was synthesized by the high-temperature solid-phase reaction. X-ray diffraction analysis was used to study the structure for the first time; the type of syngony, unit cell parameters, X-ray diffraction and pycnometric densities were determined. X-ray diffraction was carried out by homology method from the initial fluorite structure δBi2O3. The method of least squares refined the parameters of the crystal lattice. The parameters of the orthorhombic lattice of complex mixed ferrite at the value of the number of formula units Z=4 are: a=5.2319, в=5.2186, с=7.5702 Å. The correctness of the results of the X-ray diffraction of complex mixed ferrite was confirmed by the good agreement between the experimental and calculated values of the inverse squares of the interplanar distances (104/d2). Satisfactory consistency of the values of the X-ray and pycnometric densities, ρrad = 8.335, ρpik = 8.328 g/cm3, proves the correctness of the results of the experiment. A comparative analysis of the interrelation between the parameters of the crystal lattice and the parameters of the crystal lattices of the initial oxide δBi2O3. The analysis shows the values of the parameters “a” and “c” are in satisfactory agreement with the parameters of the crystal lattice δBi2O3, the parameter “c” is distorted from the value of the parameter “a” on √2.


Author(s):  
Vladimir A. Terekhov ◽  
Evgeny I. Terukov ◽  
Yury K. Undalov ◽  
Konstantin A. Barkov ◽  
Igor E. Zanin ◽  
...  

Amorphous SiOx films with silicon nanoclusters are a new interesting material from the standpoint of the physics, technology, and possible practical applications, since such films can exhibit photoluminescence due to size quantization. Moreover, the optical properties of these structures can be controlled by varying the size and the content of silicon nanoclusters in the SiOx film, as well as by transforming nanoclusters into nanocrystals by means of high-temperature annealing. However, during the annealing of nonstoichiometric silicon oxide, significant changes can occur in the phase composition and the structure of the films. The results of investigations on the crystallization of silicon nanoclusters in a SiOx matrix have shownthat, even a very fast method of annealing using PPA leads to the formation of large silicon crystallites. This also causes the crystallization of at least a part of the oxide phase in the form of silicon hydroxide H6O7Si2. Moreover, in films with an initial content of pure silicon nanoclusters ≤ 50%, during annealing a part of the silicon is spent on the formation of oxide, and part of it is spent on the formation of silicon crystals. While in a film with an initial concentration of silicon nanoclusters ≥ 53%, on the contrary, upon annealing, there occurs a partial transition of silicon from the oxide phase to the growth ofSi crystals        Reference 1. Undalov Y. K., Terukov E. I., Silicon nanoclustersncl-Si in a hydrogenated amorphous silicon suboxidematrix a-SiOx:H (0 < x < 2). Semiconductors. 2015;49(7):867- 878. DOI: https://doi.org/10.1134/S10637826150702222. Kim K. H., Johnson E. V., Kazanskii A. G.,Khenkin M. V., Roca P. Unravelling a simple methodfor the low temperature synthesis of siliconnanocrystals and monolithic nanocrystalline thinfilms. Scientific Reports. 2017;7(1) DOI: https://doi.org/10.1038/srep405533. Undalov Y. K., Terukov E. I., Trapeznikova I. N.Formation of ncl-Si in the amorphous matrix a-SiOx-:H located near the anode and on the cathode, usinga time-modulated DC plasma with the (SiH4–Ar–O2)gas phase (Co2 = 21.5 mol%). Semiconductors.2019;53(11): 1514–1523. DOI: https://doi.org/10.1134/S10637826191102284. Terekhov V. A., Terukov E. I., Undalov Y. K.,Parinova E. V., Spirin D. E., Seredin P. V., Minakov D. A.,Domashevskaya E. P. Composition and optical propertiesof amorphous a-SiOx:H films with silicon nanoclusters.Semiconductors. 2016;50(2): 212–216. DOI:https://doi.org/10.1134/S10637826160202515. Terekhov V. A., Turishchev S. Y., Kashkarov V. M.,Domashevskaya E. P., Mikhailov A. N., Tetel’baum D. I.Silicon nanocrystals in SiO2 matrix obtained by ionimplantation under cyclic dose accumulation. PhysicaE: Low-dimensional Systems and Nanostructures.2007;38(1-2): 16–20. DOI: https://doi.org/10.1016/j.physe.2006.12.0306. Terekhov V. A., Turishchev S. Y., Pankov K. N.,Zanin I. E., Domashevskaya E. P., Tetelbaum D. I.,Mikhailov A. N., Belov A. I., Nikolichev D. E., Zubkov S. Y.XANES, USXES and XPS investigations of electronenergy and atomic structure peculiarities of the siliconsuboxide thin film surface layers containing Si nanocrystals.Surface and Interface Analysis. 2010;42(6-7):891–896. DOI: https://doi.org/10.1002/sia.33387. Terekhov V. A., Turishchev S. Y., Pankov K. N.,Zanin I. E., Domashevskaya E. P., Tetelbaum, MikhailovA. N., Belov A. I., Nikolichev D. E. Synchrotron investigationsof electronic and atomic-structure peculiaritiesfor silicon-oxide films’ surface layers containingsilicon nanocrystals. Journal of Surface Investigation.X-ray, Synchrotron and Neutron Techniques. 2011;5(5):958–967. DOI: https://doi.org/10.1134/S102745101110020X8. Sato K., Izumi T., Iwase M., Show Y., Morisaki H.,Yaguchi T., Kamino T. Nucleation and growth of nanocrystallinesilicon studied by TEM, XPS and ESR.Applied Surface Science. 2003;216 (1-4): 376–381. DOI:https://doi.org/10.1016/S0169-4332(03)00445-89. Ledoux G., Gong J., Huisken F., Guillois O., ReynaudC. Photoluminescence of size-separated siliconnanocrystals: Confirmation of quantum confinement.Applied Physics Letters. 2002;80(25): 4834–4836. DOI:https://doi.org/10.1063/1.148530210. Patrone L., Nelson D., Safarov V. I., Sentis M.,Marine W., Giorgio S. Photoluminescence of siliconnanoclusters with reduced size dispersion producedby laser ablation. Journal of Applied Physics. 2000;87(8):3829–3837. DOI: https://doi.org/10.1063/1.37242111. Takeoka S., Fujii M., Hayashi S. Size-dependentphotoluminescence from surface-oxidized Si nanocrystalsin a weak confinement regime. Physical ReviewB. 2000;62(24): 16820–16825. DOI: https://doi.org/10.1103/PhysRevB.62.1682012. Ievlev V. M. Activation of solid-phase processesby radiation of gas-discharge lamps, Russian ChemicalReviews. 2013;82(9): 815–834. DOI: https://doi.org/10.1070/rc2013v082n09abeh00435713. Zimkina T. M., Fomichev V. A. Ultrasoft X-Rayspectroscopy. Leningrad: Leningrad State UniversityPubl.; 1971. 132 p.14. Wiech G., Feldhütter H. O., Šimůnek A. Electronicstructure of amorphous SiOx:H alloy filmsstudied by X-ray emission spectroscopy: Si K, Si L, andO K emission bands. Physical Review B. 1993;47(12):6981–6989. DOI: https://doi.org/10.1103/Phys-RevB.47.698115. Domashevskaya E. P., Peshkov Y. A., TerekhovV. A., Yurakov Y. A., Barkov K. A., Phase compositionof the buried silicon interlayers in the amorph o u s m u l t i l a y e r n a n o s t r u c t u r e s[(Co45Fe45Zr10)/a-Si:H]41 and [(Co45Fe45Zr10)35(Al2O3)65/a-Si:H]41. Surface and Interface Analysis.2018;50(12-13): 1265–1270. DOI: https://doi.org/10.1002/sia.651516. Terekhov V. A., Kashkarov V. M., ManukovskiiE. Yu., Schukarev A. V., Domashevskaya E. P.Determination of the phase composition of surfacelayers of porous silicon by ultrasoft X-ray spectroscopyand X-ray photoelectron spectroscopy techniques.Journal of Electron Spectroscopy and Related Phenomena.2001;114–116: 895–900. DOI: https://doi.org/10.1016/S0368-2048(00)00393-517. JCPDS-International Centre for DiffractionData ICDD PDF-2, (n.d.) card No 01-077-2110.18. JCPDS-International Centre for DiffractionData ICDD PDF-2, (n.d.) card No 00-050-0438.


2013 ◽  
Vol 56 (11) ◽  
pp. 896-904 ◽  
Author(s):  
A. Patlolla ◽  
P. Baumann ◽  
W. Xu ◽  
S. D. Senanayake ◽  
J. A. Rodriguez ◽  
...  

2011 ◽  
Vol 110 (10) ◽  
pp. 102205 ◽  
Author(s):  
J. Wollschläger ◽  
C. Deiter ◽  
C. R. Wang ◽  
B. H. Müller ◽  
K. R. Hofmann

1992 ◽  
Vol 272 ◽  
Author(s):  
Pavel E. Kolosov ◽  
A. V. Bubnov

ABSTRACTThe theoretical reduced intensity of X-ray scattering i(S) may be calculated for a cluster of any structure using Debye's formula. The comparison of both experimental determination and model calculation of the RDF or i(S) allows, to make a conclusions about structure of materials in a wide region of interatomic distances. This is a very important for direct structure characterization of giant clusters, dispersed molybdenum sulfides etc.. The simple formula for the upper limit of interatomic distances when the data are collected at equidistant step on S – scatterinrg vector, may be used for the optimal experimental conditions selection.


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