Departamento de Física
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/785
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- Anomalous Ferromagnetic Phase in the Gd1−xErxB4 Series: Crystal Growth, Thermal, and Magnetic Properties(2023-07-23) MASUNAGA, S. H.; V. B. Barbeta; ABUD, F.; TORIKACHVILI, M. S.; JARDIM, R. F.© 2023 by the authors.Rare-earth tetraborides RB4 are of great interest due to the occurrence of geometric magnetic frustration and corresponding unusual magnetic properties. While the Gd3+ spins in GdB4 align along the ab plane, Er3+ spins in the isomorphic ErB4 are confined to the c–axis. The magnetization in the latter exhibits a plateau at the midpoint of the saturation magnetization. Therefore, solid solutions of (Gd, Er)B4 provide an excellent playground for exploring the intricate magnetic behavior in these compounds. Single crystals of Gd1−xErxB4 (x = 0, 0.2, and 0.4) were grown in aluminum flux. X-ray diffraction scans revealed single-phase materials, and a drop in the unit cell volume with increasing Er content, suggesting the partial substitution of Er at the Gd sites. Heat capacity measurements indicated a systematic decrease of the Néel temperature (TN) with increasing Er content. The effective magnetic moment determined from the magnetization measurement agreed with the calculated free ion values for Gd3+ and Er3+, providing further evidence for the successful substitution of Er for Gd. The partial substitution resulted in an anomalous ferromagnetic phase below TN, exhibiting significant anisotropy, predominantly along the c-axis. This intriguing behavior merits further studies of the magnetism in the Gd1−xErxB4 borides.
- The NUMEN project @ LNS: Status and perspectives(2019-09-03) CAPPUZZELLO, F.; AGODI, C.; ACOSTA, L.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J. I.; BELMONT, D.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOZTOSUN, I.; BRANCHINA, V.; BRASOLI, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; CHEN, R.; CIRALDO, I.; LOMELI, E. R. C.; COLONNA, M.; D'AGOSTINO, G.; DJAPO, H.; DE GERONIMO, G.; DELAUNAY, F.; DESHMUKN, N.; DE FARIA, P. N.; ESPEJEL, R.; FERRARESI, C.; FERREIRA, J. L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FLORES, A.; FOTI, A.; GALLO, G.; GARCIA-TECOCOATZI, H.; GONGORA, B.; HACISALIHOGLU, A.; HAZAR, S.; HUERTA, A.; KOTILA, J.; KUCUK, Y.; IAZZI, F.; LANZALONE, G.; LA VIA, F.; LAY, J. A.; LENSKE, H.; LINARES, R.; LONGHITANO, F.; LO PRESTI, D.; LUBIAN, J.; MA, J.; MARIN-LAMBARRI, D.; MARTINEZ, S.; MAS, J.; MEDINA, N. H.; MENDES, D. R.; MEREU, P.; MORALLES, M.; OLIVEIRA, J. R. B.; ORDONEZ, C.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PIETRALLA, N.; PINNA, F.; REITO, S.; REZA, G.; RIES, P.; RIFUGGIATO, D.; RODRIGUES, M. R. D.; RUSSO, A. D.; RUSSO, G.; SANDOVAL, S.; SANTOPINTO, E.; Roberto Santos; SGOUROS, O.; Marcilei Aparecida Guazzelli; SOLAKCI, S. O.; SOULIOTIS, G.; SOUKERA, V.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; VSEVOLODOVNA, R. I. M.; VARGAS, H.; VEGA, G.; WANG, J. S.; WERNER, V.; YANG, Y. Y.; YILDIRIN, A.; ZAGATTO, V. A. B.© 2019 Author(s).The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0υββ), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. Particular interest is given to the (18O,18Ne) and (20Ne,20O) reactions as tools for β+ β+ and β-β- decays, respectively. First evidence about the possibility to get quantitative information about NME from experiments is found for both kind of reactions. In the experiments, performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction products are detected by the MAGNEX magnetic spectrometer. The measured cross sections are challengingly low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to significantly increase the experimental yield, thus making feasible a systematic study of all the cases of interest. Frontiers technologies are going to be developed, to this purpose, for the accelerator and the detection systems. In parallel, advanced theoretical models are developed aiming at extracting the nuclear structure information from the measured cross sections.
- The NUMEN project @ LNS: Status and perspectives(2019-09-03) CAPPUZZELLO, F.; AGODI, C.; ACOSTA, L.; ALTANA, C.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOZTOSUN, I.; BRANCHINA, V.; BRASOLIN, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; GARCIA,L. E. C.; LOMELI, E. R. C.; CHEN, R.; CIRALDO, I.; COLONNA, M.; D'AGOSTINO, G.; DELAUNAY, F.; DESHMUKH, N.; DJAPO, H.; DE GERONIMO, G.; DE LOS RIOS, K.; FERRARESI, C.; FERREIRA, J. L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FOTI, A.; GALLO, G.; GARCIA-TECOCOATZI, H.; HACISALIHOGLU, A.; HUERTA-HERNANDEZ, A.; KOTILA, Z. J.; KUCUK, Y.; IAZZI, F.; LANZALONE, G.; LAY, J. A.; LA FAUCI, L.; LA VIA, F.; LENSKE, H.; LINARES, R.; LO PRESTI, D.; LUBIAN, J.; MA. J.; MARIN-LAMBARRI, D.; RUIZ, J. M.; MEDINA, N. H.; MENDES, D. R.; MEREU, P.; MORALLES, M.; NERI, L.; OLIVEIRA, J. R. B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PIETRALLA, N.; PINNA, F.; REITO, S.; RIES, P.; RODRIGUES, M. R. D.; RUSSO, A. D.; RUSSO, G.; SANTOPINTO, E.; Roberto Santos; SERBINA, L.; SGOUROS, O.; Marcilei Aparecida Guazzelli; SOLAKCL, S. O.; SOULIOTIS, G.; SOUKERAS, V.; SPATAFORA, A.; TORRESI, D.; TUDISCO, S.; HERNANDEZ, H. V.; VSEVOLODOVNA, R. I. M.; WANG, J. S.; WERNER, V.; YANG, Y. Y.; YILDIRIN, A.; ZAGATTO, V. A. B.© 2019 Author(s).The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ), by high-accuracy measurements of Heavy Ion (HI) induced Double Charge Exchange (DCE) reaction cross sections. In particular, the (18O,18Ne) and (20Ne,20O) reactions are used as tools for β+β+ and β-β- decays, respectively. In the experiments, performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction ejectiles are detected the MAGNEX magnetic spectrometer. The measured cross sections are challengingly low (a few nb), being the total reaction cross section much larger (a few b), thus a high sensitivity and a large rejection capability are demanded to the experimental set-up. This limits the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to increase the experimental yield of at least two orders of magnitude, still keeping the high sensitivity of the present set-up, making it feasible a systematic study of all the cases of interest. Frontiers technologies are going to be developed, to this purpose, for the accelerator and the detection systems. In parallel, advanced theoretical models are being developed in order to extract the nuclear structure information from the measured cross sections.
Artigo de evento 3 Citação(ões) na Scopus Radiation effect mechanisms in electronic devices(2013-12-01) Marcilei Aparecida Guazzelli; Roberto Santos; LEITE, F.; CUNHA, F.; CIRNE, K. H.; MEDINA, N. H.; ADDED, N.; AGUIAR, V. A. P.© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.In this work, P- and N-MOSFETs (Metal Oxide Semiconductor Field Effect Transistor) were submitted to X-ray and ion beams. CD 4007, a commercial off-the-shelf integrated circuit composed of six transistors, three P-type and three N-type, in a single package, was used. The integrated circuits were exposed to 60 MeV 35Cl ion beams using the São Paulo 8UD Pelletron Accelerator and 10 keV X-ray radiation, using a Shimadzu XRD-7000 X-ray diffractometer. The total dose effects due to ionizing radiation in MOSFET were analyzed. The results indicate Vth depends on the absorbed dose and dose rate. The deviation of Vth is higher for P-MOS, while the change in slope is higher for N-MOS. TID (Total Ionizing Dose) caused by heavy ion does not seem to affect mobility. After heat treatment, the device establishes a different equilibrium state compared to that achieved at room temperature. The heat treatment worsens the P-type characteristics and improves the N-type.Artigo de evento 1 Citação(ões) na Scopus Titanium extraction from waste NORM(2013-12-01) PEREIRA, B. R.; Marcilei Aparecida Guazzelli; FONTANA, G.; Roberto Santos; RIZZUTTO, M. A.; MEDINA, N. H.© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.The constantly growing of global agricultural production depends on the development of a whole production to be lasting and sustainable. The phosphoric acid production is directly related to the production of fertilizers, but its process of obtaining requires numerous steps and generates a lot of waste. There are several elements in some of these wastes that are very valuable and important for economy and for technological development. An example is a residue derived from a step of physical handling of the phosphate rock, containing about 30% of titanium in its composition. Titanium can be used in various applications, such as a component in high-tech metallic alloys, or, in the form of titanium dioxide, which is the form that presents the greatest value in industry. This study focus at the concentration of titanium oxide present in a residue from the phosphoric acid production, by attacking the material chemically and doing its characterization by analytical methods. This would contribute to the national titanium concentrated production increased and enhance the economic yield of the phosphoric acid production process, by transforming an unused waste in a high value product. The methodology for the concentration of titanium oxide was based in industrial extraction of titanium ores and consists of solubilizing the impurities present in the sample by means of chemical attack. It has been determined experimentally that at temperatures around 70°C, hydrochloric acid provides a better solubilization of impurities, without extracting titanium, and it is possible to obtain a residual solid phase with about 58.5% of titanium on it. The results were determined by using the Energy Dispersive X-Ray Fluorescence (EDXRF) technique. As the original sample is a Normal Occurring Radioactive Material (NORM), an analysis of Gamma Ray Spectroscopy and EDXRF were realized to determine how the radionuclides form the U and Th series were affected by the chemical treatment.Artigo 0 Citação(ões) na Scopus Parasitic conduction response to X-ray radiation in unstrained and strained triple-gate SOI MuGFETs(2014-05-05) TEIXEIRA, F. F.; BORDALLO, C. C. M.; Marcilei Aparecida Guazzelli; AGOPIAN, P. G. D.; MARTINO, J. A.; SIMOEN, E.; CLAEYS, C.© 2014, Journal of Integrated Circuits and Systems. All rights reserved.In this work, the X-ray irradiation impact on the back gate conduction and drain current for Triple-Gate SOI FinFETs is investigated for strained and unstrained devices. Both types (P and N) of transistors were analyzed. Since X-rays promote trapped positive charges in the buried oxide, the second interface threshold voltage shifts to lower gate voltage. The performance of n-channel devices presented a strong degradation when submitted to X-rays, while for p-channel devices the opposite trend was observed. Two different dose rates were analyzed.Artigo 2 Citação(ões) na Scopus The influence of back gate bias on the OCTO SOI MOSFET’s response to X-ray radiation(2015-09-10) FINO, L. M. S.; Marcilei Aparecida Guazzelli; RENAUX, C.; FLANDRE, D.; Salvador Gimenez© 2015 Brazilian Microelectronics Society. All rights reserved.This work investigates the X-ray irradiation impact on the performance of an on-conventional transistor called OCTO SOI MOSFET that adopts an octagonal gate shape instead of a rectangular. The electrical behaviors of both devices were studied through an experimental comparative analysis of the total ionizing dose influence. In addition, the back-gate bias technique was applied in these devices to reestablish its threshold voltages and drain currents conditions that were degraded due the trapping of positive charges in the buried oxide. As the main finding of this work, after the irradiation procedure, we notice that the OCTO device is capable to reestablish its prerad electrical behavior with a smaller back gate bias than the one observed in the standard one counterpart. This is mainly because the parasitic transistors in the bird’s beak region are practically deactivated due the particular octagonal gate geometry.- Evaluating the Reliability of Different Voting Schemes for Fault Tolerant Approximate Systems(2023-06-20) BALEN, T. R.; GONZALEZ, C. J.; OLIVEIRA, I. F. V.; DA ROSA JR. L. S.; SOARES, R. I.; SCHVITTZ, R. B.; ADDED, N.; MACCHIONE, E. L. A.; AGUIAR, V. A. P.; Marcilei Aparecida Guazzelli; MEDINA, N. H.; BUTZEN, P. F.© 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.This work presents a study on the reliability of voters for approximate fault tolerant systems in the context of single event effects and electromagnetic interference. A first case study analyses different topologies of single-bit majority voters for logic circuits employing fault injection by simulation. In these simulations, an analysis is first performed to identify the critical diffusion areas of the physical implementation according to the voter input vector. Additionally, as a second case study, practical heavy ion experiments on different architectures of software-based approximate voters for mixed-signal applications are also presented, and the cross section of each voter is evaluated. The system comprising the voters was irradiated in two distinct experiments with an 16O ion beam, producing an effective LET at the active region of 5.5 MeV/mg/cm 2 . As a complementary study, a conducted electromagnetic interference injection was also performed, considering two distinct voting schemes. Results of the case-studies allow identifying the most tolerant voter architectures (among the studied ones) for approximate computing applications under single event effects and electromagnetic interference.
- Modeling of MOSFETs Altered by Ionizing Radiation Using Artificial Neural Networks(2023-08-05) SANTOS, L. S. A. DOS; ALLEGRO, P. R. P.; Marcilei Aparecida Guazzelli; GUIDI, A. L.; G. JUNIOR, P. R.; A. JUNIOR, V. S.; TOUFEN, D. L.; VILAS BOAS, A. C.© 2023, The Author(s) under exclusive licence to Sociedade Brasileira de Física.The ionizing radiation absorbed by semiconductor devices can change their properties by modifying their electrical parameters and, in the case of memories, it can modify the information contained in these components. Thus, the ability to predict how ionizing radiation affects electronic circuits becomes especially important in environments where there is the possibility of prolonged exposure to intense radiation, such as satellites, nuclear reactors, particle accelerators, and medical equipment, among others. In this sense, this paper proposes a methodology to reproduce the behavior of TID (total ionizing dose) damaged MOSFET transistors using the fully connected artificial neural networks, taking advantage of its universal estimator characteristics to oversample the dataset’s pattern and give it a better resolution. The dataset complexity requires a specific architecture choice, being necessary the use of two neural network models to separately reproduce the MOSFET electric current magnitude order and its curve shape. Results show a very good capability to reproduce and interpolate the MOSFET behavior, which makes the proposed method a promising way to simulate circuits based on MOSFETs that are exposed to ionizing radiation.
- New experimental campaign of NUMEN project(2019-09-05) AGODI, C.; CAPPUZZELLO, F.; ACOSTA, L.; AMADOR-VALENZUELA, P.; AUERBACH, N.; BAREA, J.; BELLONE, J. I.; BELMONT, D.; BIJKER, R.; BONANNO, D.; BORELLO-LEWIN, T.; BOSTOZUN, I.; BRANCHINA, V.; BRASOLIN, S.; BRISCHETTO, G.; BRUNASSO, O.; BURRELLO, S.; CALABRESE, S.; CALABRETTA, L.; CALVO, D.; CAPIROSSI, V.; CARBONE, D.; CAVALLARO, M.; CHEN, R.; CIRALDO, I.; LOMELI, E. R. C.; COLONNA, M.; D' AGOSTINO, G.; DJAPO, H.; DE GERONIMO, G.; DELAUNAY, F.; DESHMUKH, N.; DE FARIA, P. N.; ESPEJEL, R.; FERRARESI, C.; FERREIRA, J. L.; FERRETTI, J.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA M.; FLORES A.; FOTI A.; GALLO G.; GARCIA-TECOCOATZI H.; GONGORA B.; HACISALIHOGLU A.; HAZAR S.; HUERTA A.; KOTIJA J.; KUCUK Y.; IAZZI F.; LANZALONE G.; LA VIA F.; LAY J. A.; LENSKE H.; LINARES R.; LONGHITANO F.; LO PRESTI D.; LUBIAN J.; MA J.; MARIN-LAMBARRI D.; MATINEZ S.; MEDINA N. H.; MENDES D. R.; MEREU P.; MORALLES M.; OLIVEIRA J. R. B.; ORDONEZ C.; PAKOU A.; PANDOLA L.; PETRASCU H.; PIETRALLA N.; PINNA F.; REITO S.; REZA G.; RIES P.; RIFUGGIATO D.; RODRIGUES M. R. D.; RUSSO A. D.; RUSSO G.; SANDOVAL S.; SANTOPINTO E.; Roberto Santos; SGOUROS O.; Marcilei Aparecida Guazzelli; SOLAKCI S. O.; SOULIOTIS G.; SOUKERAS V.; SPATAFORA A.; TORRESI D.; TUDISCO S.; VSEVOLODOVNA R. I. M.; VARGA H.; VEGA G.; WANG J. S.; WERNER V.; YANG Y. Y.; YILDIRIN A.; ZAGATTO V. A. B.© 2019 Author(s).The NUMEN main goal is the extraction from measured cross-sections of "data-driven" information on Nuclear Matrix Elements for all the systems candidate for 0νββ. The idea is to use as experimental tool Heavy Ions -Double Charge Exchange (HI-DCE) reactions. Crucial for the experimental challanges is the INFN Laboratori Nazionali del Sud (LNS) facility, made by the Superconducting Cyclotron (CS) and the MAGNEX magnetic spectrometer. The experimental measurements of HI-DCE reactions present a number of challenging aspects, since they are characterized by very low cross sections. Here it is reported the new experimental campaign of NUMEN Project.