Records |
Author |
Abreu, Y.; Cruz, C.M.; Pinera, I.; Leyva, A.; Cabal, A.E.; van Espen, P. |
Title |
DFT study of the hyperfine parameters and magnetic properties of ZnO doped with 57Fe |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Solid state communications |
Abbreviated Journal |
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Volume |
185 |
Issue |
|
Pages |
25-29 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Magnetic state of Fe-57 implanted and doped ZnO samples have been reported and studied by Mossbauer spectroscopy at different temperatures. The Mossbauer spectra mainly showed four doublets and three sextets, but some ambiguous identification remains regarding the probe site location and influence of defects in the hyperfine and magnetic parameters. In the present work some possible implantation configurations are suggested and evaluated using Monte Carlo simulation and electronic structure calculations within the density functional theory. Various implantation environments were proposed and studied considering the presence of defects. The obtained Fe-57 hyperfine parameters show a good agreement with the reported experimental values for some of these configurations. The possibility of Fe pair formation, as well as a Zn site vacancy stabilization between he second and third neighborhood of the implantation site, is supported. (C) 2014 Elsevier Ltd. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000333751400007 |
Publication Date |
2014-01-23 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0038-1098 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:116839 |
Serial |
7806 |
Permanent link to this record |
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Author |
Pinera, I.; Cruz, C.M.; Abreu, Y.; Leyva, A.; van Espen, P.; Diaz, A.; Cabal, A.E.; Van Remortel, N. |
Title |
Gamma induced atom displacements in LYSO and LuYAP crystals as used in medical imaging applications |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Interactions With Materials And Atoms |
Abbreviated Journal |
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Volume |
356 |
Issue |
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Pages |
46-52 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Particle Physics Group; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
The radiation damage, in terms of atom displacements, induced by gamma irradiation in LYSO and LuYAP crystals is presented. Sc-44, Na-22 and V-48 are used as gamma sources for this study. The energy of gammas from the electron positron annihilation processes (511 keV) is also included in the study. The atom displacements distributions inside each material are calculated following the Monte Carlo assisted Classical Method introduced by the authors. This procedure also allows to study the atom displacements in-depth distributions inside each crystal. The atom displacements damage in LYSO crystals is found to be higher than in LuYAP crystals, mainly provoked by the displacements of silicon and oxygen atoms. But the difference between atom displacements produced in LYSO and LuYAP decreases when more energetic sources are used. On the other hand, the correlation between the atom displacements and energy deposition in-depth distributions is excellent. The atom displacements to energy deposition ratio is found to increases with more energetic photon sources. LYSO crystals are then more liable to the atom displacements damage than LuYAP crystals. (C) 2015 Elsevier B.V. All rights reserved. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000356990400008 |
Publication Date |
2015-05-14 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0168-583x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:127012 |
Serial |
7987 |
Permanent link to this record |
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Author |
Abreu, Y.; Cruz, C.M.; Pinera, I.; Leyva, A.; Cabal, A.E.; van Espen, P.; Van Remortel, N. |
Title |
Hyperfine electric parameters calculation in Si samples implanted with 57Mn\rightarrow57Fe |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Physica: B : condensed matter |
Abbreviated Journal |
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Volume |
445 |
Issue |
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Pages |
1-4 |
Keywords |
A1 Journal article; Particle Physics Group; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Nowadays the electronic structure calculations allow the study of complex systems determining the hyperfine parameters measured at a probe atom, including the presence of crystalline defects. The hyperfine electric parameters have been measured by Mossbauer spectroscopy in silicon materials implanted with Mn-57 ->,Fe-57 ions, observing four main contributions to the spectra. Nevertheless, some ambiguities still remain in the Fe-57 Mossbauer spectra interpretation in this case, regarding the damage configurations and its evolution with annealing. In the present work several implantation environments are evaluated and the Fe-57 hyperfine parameters are calculated. The observed correlation among the studied local environments and the experimental observations is presented, and a tentative microscopic description of the behavior and thermal evolution of the characteristic defects local environments of the probe atoms concerning the location of vacancies and interstitial Si in the neighborhood of Fe-57 ions in substitutional and interstitial sites is proposed. (C) 2014 Elsevier B.V. All rights reserved |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000336478700001 |
Publication Date |
2014-03-22 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0921-4526; 1873-2135 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:117697 |
Serial |
8046 |
Permanent link to this record |
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Author |
Pinera, I.; Cruz, C.M.; Leyva, A.; Abreu, Y.; Cabal, A.E.; van Espen, P.; Van Remortel, N. |
Title |
Improved calculation of displacements per atom cross section in solids by gamma and electron irradiation |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Interactions With Materials And Atoms |
Abbreviated Journal |
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Volume |
339 |
Issue |
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Pages |
1-7 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Particle Physics Group; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Several authors had estimated the displacements per atom cross sections under different approximations and models, including most of the main gamma- and electron-material interaction processes. These previous works used numerical approximation formulas which are applicable for limited energy ranges. We proposed the Monte Carlo assisted Classical Method (MCCM), which relates the established theories about atom displacements to the electron and positron secondary fluence distributions calculated from the Monte Carlo simulation. In this study the MCCM procedure is adapted in order to estimate the displacements per atom cross sections for gamma and electron irradiation. The results obtained through this procedure are compared with previous theoretical calculations. An improvement in about 10-90% for the gamma irradiation induced dpa cross section is observed in our results on regard to the previous evaluations for the studied incident energies. On the other hand, the dpa cross section values produced by irradiation with electrons are improved by our calculations in about 5-50% when compared with the theoretical approximations. When thin samples are irradiated with electrons, more precise results are obtained through the MCCM (in about 20-70%) with respect to the previous studies. (C) 2014 Elsevier B.V. All rights reserved. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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Language |
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Wos |
000343785500001 |
Publication Date |
2014-09-15 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0168-583x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:121161 |
Serial |
8069 |
Permanent link to this record |