Magnetic properties and structural characterization of CoxFe(1−x)Al Heusler alloys synthesized from Co/FeAl multilayers L. H. F. Andrade, L. M. B. Campos, T. A. Pedrosa, A. Krohling, J. D. Ardisson, et al. Aip Advances, 2025 Thin CoxFe(1−x)Al (CFA) alloy films with varying thicknesses (34 nm < d < 219 nm) were prepared on Ta/SiO2/Si substrates at room temperature (RT) and at 620 K by alternating sputtering layers from Co and Fe0.5Al0.5 targets, followed by in situ annealing of the sputtered multilayers at higher temperatures in ultrahigh vacuum. The films were synthesized by magnetron sputtering in a ultra-high vacuum chamber and the deposition was carried out at room temperature (RT) and at 620 K. X-ray diffraction (XRD), energy-dispersive x-ray spectroscopy, magneto-optical Kerr effect investigations, and Mössbauer spectroscopy revealed that the structural, magnetic properties, and composition of the synthesized alloys are highly sensitive to growth temperature, film thickness, annealing conditions, and the number of multilayers (ML) annealed. The XRD measurements demonstrated that films with B2 chemical ordering were obtained for stacks with total thickness smaller than 100 nm and under optimal growth and annealing conditions. The magnetic properties of the samples were investigated using magneto-optic Kerr effect and Mössbauer spectroscopy, showing that after appropriate annealing, films exhibit ferromagnetic character for synthesized films with thickness below 100 nm. Polycrystalline CFA alloys synthesized from Co/FeAl multilayers over Ta/SiO2/Si substrates exhibit dominant uniaxial in-plane anisotropy (UMA), which is independent of chemical order and growth temperature. The UMA is less pronounced for thicker films, suggesting that surface effects are related to the uniaxial magnetic anisotropy observed and that either the number of interfaces, grain size, or grain boundaries have a greater influence than thickness for obtaining the B2 phase in Co/FeAl stacks by annealing.
Analysis of mechanical and biological properties of fast setting time nanostructured biphasic calcium phosphate bone cement Marcelo Augusto Brito Madureira, Katia Michelle Freitas, Camila de Lima Cruz, Tércio Assunção Pedrosa, Rafael Lopes, et al. Revista Materia, 2020 RESUMO Nas últimas duas décadas intensificaram-se os estudos para desenvolvimento de novas terapêuticas para aplicações em doenças degenerativas do tecido ósseo, bem como formas menos invasivas de tratamentos de traumas de acidentes viários. Neste cenário, biocimentos de fosfato de cálcio (CFCs) de cura rápida para aplicações injetáveis e/ou moldáveis, permitem o uso através de técnicas cirúrgicas minimamente invasivas. Matrizes de CFCs têm atraído grande interesse para uso em ortopedia e odontologia como substitutos para partes danificadas do sistema osteocondral, permitindo sua utilização na reparação ou preenchimento ósseo. Neste trabalho foram processados CFCs constituídos por dois diferentes fosfatos de cálcio bifásicos (BCP), um com distribuição micrométrica e outro com distribuição nanométrica, fosfato de sódio e carboximetilcelulose, visando a utilização deste material em procedimentos cirúrgicos. As matérias primas foram caracterizadas físico-quimicamente por difração de raio X, microscopia eletrônica de varredura acoplada com espectroscopia de energia dispersiva de raios X. O tempo de pega do material foi avaliado pelo ensaio de Vicat e a resistência mecânica do CFC foi avaliada através dos ensaios de Flexão (resistência mecânica a tração) e Ultramicrodureza (módulo de elasticidade). As propriedades biológicas foram avaliadas através dos ensaios in vitro de degradação em solução Tris-HCL e citotoxicidade em cultura de bactérias e ensaio in vivo pelo método de HET-CAM. Os resultados mostraram um melhor desempenho do BCP nanométrico, tendo tempo de pega final baixo, 22 minutos, e resistência mecânica da ordem de 4 MPa, compatível com a expectativa esperada para osso esponjoso. Os ensaios biológicos confirmaram a resposta biológica satisfatória destes nanocompósitos. Isso demonstra que o material tem potencial para aplicação clínica em substituição ao cimento acrílico hoje largamente utilizado.
Selenized Saccharomyces cerevisiae cells are a green dispenser of nanoparticles Alline Gomes Pereira, Luanai Grazieli Luquini Gerolis, Letícia Satler Gonçalves, Tércio Assunção Pedrosa, Maria José Neves Biomedical Physics and Engineering Express, 2018 Selenized Saccharomyces cerevisiae cells are used as a nutritional supplement for humans and animals since they contain large amounts of selenomethionine. Although it has been discussed less frequently, they also have a considerable quantity of selenium nanoparticles (Se-NP). Se-NP were generated inside cells after 48 h of incubation with sodium selenite; these nanoparticles were shown to have a spherical morphology, with an estimated size of 20–30 nm, and were mainly made up of Se. The type of Se-NP produced inside the cells depends on the new protein synthesis. They are amorphous, and are generated regardless of the presence of light or oxygen. After its intracellular generation, Se-NP move to the extracellular compartment, without compromising membrane integrity in aerobic conditions. The release of Se-NP from cells was time dependent.
Effects of heat treatments on the thermal diffusivity of Uranium-Molybdenum alloy D M Camarano, F A Mansur, A M M Santos, W B Ferraz, T A Pedrosa Journal of Physics Conference Series, 2016 U-Mo alloys are the most investigated nuclear fuel material to be used in research reactors. The addition of molybdenum stabilizes the gamma phase of uranium and increases its melting point. A research program under development at Nuclear Technology Development Center (CDTN) aims the obtaining of uranium-molybdenum alloys to enable the high enriched uranium (HEU) to low enriched uranium (LEU) conversions. U-Mo ingots with 10% by weight were induction melted and heat treated at 300 °C for 72 h, 120 h and 240 h. Thermal diffusivity was determined by the laser flash method and thermal quadrupole method, from room temperature to 300 oC and 400oC. It was observed that the thermal diffusivity tends to increase with increasing temperature.
Rare earth element (REE)-enriched granitic pegmatite pockets of Lagoa Real Uranium Province, Brazil TH DeFerreira, LAR de Oliveira, LED Amorim, TA Pedrosa, FJ Rios Geochemistry 81 (4), 125810 , 2021 2021 Citations: 4
Melt-melt immiscibility and implications for the origin of Madeira albite-rich granite, Pitinga mine, Amazonas, Brazil: A melt inclusion study RMK Borges, LED Amorim, FJ Rios, GCS Santos, ME Freitas, TAF Lima, ... Brazilian Journal of Geology 51, e20210011 , 2021 2021 Citations: 3
Análise das propriedades mecânicas e biológicas do cimento ósseo de fosfato de cálcio bifásico nanoestruturado de cura rápida MAB Madureira, KM Freitas, CL Cruz, TA Pedrosa, R Lopes, SN Silva, ... Matéria (Rio de Janeiro) 25 (04), e-12859 , 2020 2020 Citations: 1
Analysis of mechanical and biological properties of fast setting time nanostructured biphasic calcium phosphate bone cement MAB Madureira, KM Freitas, CL Cruz, TA Pedrosa, R Lopes, SN Silva, ... Matéria (Rio de Janeiro) 25, e-12859 , 2020 2020 Citations: 1
Mineralogical characterization and origin of uranium mineralization in Witwatersrand-like metaconglomerate of the Moeda Formation, Quadrilátero Ferrífero, Brazil FS Guimarães, ME de Freitas, FJ Rios, TA Pedrosa Ore geology reviews 106, 423-445 , 2019 2019 Citations: 5
Growth of Gd2O3 coherent layers on UO2 microsphere surface via sol-gel process LS Ribeiro, EF Silva, FWF Oliveira, YS Pereira, AFC Brandão, ... Associação Brasileira de Energia Nuclear (ABEN), Rio de Janeiro, RJ (Brazil) , 2017 2017
Evaluation of AS-CAST U-Mo alloys processed in graphite crucible coated with boron nitride KM Marra, SC Reis, JB Paula, TA Pedrosa Associação Brasileira de Energia Nuclear (ABEN), Rio de Janeiro, RJ (Brazil) , 2017 2017 Citations: 2
Effects of heat treatments on the thermal diffusivity of Uranium-Molybdenum alloy DM Camarano, FA Mansur, AMM Santos, WB Ferraz, TA Pedrosa Journal of Physics: Conference Series 733 (1), 012014 , 2016 2016
Phase transitions during artificial ageing of segregated as-cast U–Mo alloys TA Pedrosa, AMM dos Santos, FS Lameiras, PR Cetlin, WB Ferraz Journal of Nuclear Materials 457, 100-117 , 2015 2015 Citations: 34
Compressive and Shearing Mechanical Anisotropy of Aluminum after ECAP CG de Faria, TA Pedrosa, RB Figueiredo, MTP Aguilar, PR Cetlin Advanced Materials Research 1016, 100-104 , 2014 2014 Citations: 1
Influence of the Hydriding Cycles on U-10Mo Alloy Comminution Process KCM Faêda, TA Pedrosa, NM Cantagalli, FS Lameiras, WB Ferraz Journal of Energy and Power Engineering 8 (9) , 2014 2014
Preliminary results for the co-rolling process fabrication of plate-type nuclear fuel based in U-10Mo monolithic meat and zircaloy-4 cladding TA Pedrosa, JGM Brina, JB Paula, FS Lameiras, WB Ferraz Associacao Brasileira de Energia Nuclear (ABEN), Rio de Janeiro, RJ (Brazil) , 2013 2013 Citations: 3
Comminution of the U-10Mo by hydriding cycles innovative process K Faeda, AMM Santos, JB Paula, EM Pereira, TA Pedrosa, FS Lameiras, ... Associacao Brasileira de Energia Nuclear (ABEN), Rio de Janeiro, RJ (Brazil) , 2013 2013
Investigation of the microstructure influence in the thermo-physical properties of U-Mo alloys through the laser flash method TA Pedrosa, FF Alves, PF Kelmer, AMM Santos, DM Camarano, ... Associacao Brasileira de Energia Nuclear (ABEN), Rio de Janeiro, RJ (Brazil) , 2013 2013 Citations: 1
Distortion in quenching an AISI 4140 C-ring–Predictions and experiments AD Da Silva, TA Pedrosa, JL Gonzalez-Mendez, X Jiang, PR Cetlin, ... Materials & Design 42, 55-61 , 2012 2012 Citations: 98
Obtention of uranium-molybdenum alloy ingots microstructure and phase characterization TA Pedrosa, DM Braga, JB Paula, JGM Brina, WB Ferraz 2011 Citations: 1
Obtention of uranium-molybdenum alloy ingots technique to avoid carbon contamination TA Pedrosa, JB Paula, SC Reis, JGM Brina, KCM Faeda, WB Ferraz Associacao Brasileira de Energia Nuclear, Rio de Janeiro, RJ (Brazil) , 2011 2011
Thermophysical properties determination of uranium-molybdenum fuel by the flash laser method RAN Ferreira, DM Camarano, O Miranda, PA Grossi, L Carneiro, ... Associacao Brasileira de Energia Nuclear, Rio de Janeiro, RJ (Brazil) , 2011 2011 Citations: 1
THE EVALUATION OF FLOW IRREGULARITIES IN THE AXISYMMETRIC DRAWING OF BARS THROUGH THE FINITE ELEMENT METHOD TA Pedrosa, AEM Pertence, HB Campos, PR Cetlin 61 DG Congresso Anual da Associacao Brasileira de Metalurgia e Materiais: 61 … , 2006 2006
THE COMPARISON OF NUMERICAL AND EXPERIMENTAL RESULTS FOR BULGING AND CONVERGENCE IN THE DRAWING OF CYLINDRICAL BARS TA Pedrosa, AE de Melo Pertence, HB Campos, PR Cetlin 60 DG Congresso Anual da Associacao Brasileira de Metalurgia e Materiais: 60 … , 2005 2005
MOST CITED SCHOLAR PUBLICATIONS
Distortion in quenching an AISI 4140 C-ring–Predictions and experiments AD Da Silva, TA Pedrosa, JL Gonzalez-Mendez, X Jiang, PR Cetlin, ... Materials & Design 42, 55-61 , 2012 2012 Citations: 98
Phase transitions during artificial ageing of segregated as-cast U–Mo alloys TA Pedrosa, AMM dos Santos, FS Lameiras, PR Cetlin, WB Ferraz Journal of Nuclear Materials 457, 100-117 , 2015 2015 Citations: 34
Mineralogical characterization and origin of uranium mineralization in Witwatersrand-like metaconglomerate of the Moeda Formation, Quadrilátero Ferrífero, Brazil FS Guimarães, ME de Freitas, FJ Rios, TA Pedrosa Ore geology reviews 106, 423-445 , 2019 2019 Citations: 5
Rare earth element (REE)-enriched granitic pegmatite pockets of Lagoa Real Uranium Province, Brazil TH DeFerreira, LAR de Oliveira, LED Amorim, TA Pedrosa, FJ Rios Geochemistry 81 (4), 125810 , 2021 2021 Citations: 4
Melt-melt immiscibility and implications for the origin of Madeira albite-rich granite, Pitinga mine, Amazonas, Brazil: A melt inclusion study RMK Borges, LED Amorim, FJ Rios, GCS Santos, ME Freitas, TAF Lima, ... Brazilian Journal of Geology 51, e20210011 , 2021 2021 Citations: 3
Preliminary results for the co-rolling process fabrication of plate-type nuclear fuel based in U-10Mo monolithic meat and zircaloy-4 cladding TA Pedrosa, JGM Brina, JB Paula, FS Lameiras, WB Ferraz Associacao Brasileira de Energia Nuclear (ABEN), Rio de Janeiro, RJ (Brazil) , 2013 2013 Citations: 3
Evaluation of AS-CAST U-Mo alloys processed in graphite crucible coated with boron nitride KM Marra, SC Reis, JB Paula, TA Pedrosa Associação Brasileira de Energia Nuclear (ABEN), Rio de Janeiro, RJ (Brazil) , 2017 2017 Citations: 2
Análise das propriedades mecânicas e biológicas do cimento ósseo de fosfato de cálcio bifásico nanoestruturado de cura rápida MAB Madureira, KM Freitas, CL Cruz, TA Pedrosa, R Lopes, SN Silva, ... Matéria (Rio de Janeiro) 25 (04), e-12859 , 2020 2020 Citations: 1
Analysis of mechanical and biological properties of fast setting time nanostructured biphasic calcium phosphate bone cement MAB Madureira, KM Freitas, CL Cruz, TA Pedrosa, R Lopes, SN Silva, ... Matéria (Rio de Janeiro) 25, e-12859 , 2020 2020 Citations: 1
Compressive and Shearing Mechanical Anisotropy of Aluminum after ECAP CG de Faria, TA Pedrosa, RB Figueiredo, MTP Aguilar, PR Cetlin Advanced Materials Research 1016, 100-104 , 2014 2014 Citations: 1
Investigation of the microstructure influence in the thermo-physical properties of U-Mo alloys through the laser flash method TA Pedrosa, FF Alves, PF Kelmer, AMM Santos, DM Camarano, ... Associacao Brasileira de Energia Nuclear (ABEN), Rio de Janeiro, RJ (Brazil) , 2013 2013 Citations: 1
Obtention of uranium-molybdenum alloy ingots microstructure and phase characterization TA Pedrosa, DM Braga, JB Paula, JGM Brina, WB Ferraz 2011 Citations: 1
Thermophysical properties determination of uranium-molybdenum fuel by the flash laser method RAN Ferreira, DM Camarano, O Miranda, PA Grossi, L Carneiro, ... Associacao Brasileira de Energia Nuclear, Rio de Janeiro, RJ (Brazil) , 2011 2011 Citations: 1
Growth of Gd2O3 coherent layers on UO2 microsphere surface via sol-gel process LS Ribeiro, EF Silva, FWF Oliveira, YS Pereira, AFC Brandão, ... Associação Brasileira de Energia Nuclear (ABEN), Rio de Janeiro, RJ (Brazil) , 2017 2017
Effects of heat treatments on the thermal diffusivity of Uranium-Molybdenum alloy DM Camarano, FA Mansur, AMM Santos, WB Ferraz, TA Pedrosa Journal of Physics: Conference Series 733 (1), 012014 , 2016 2016
Influence of the Hydriding Cycles on U-10Mo Alloy Comminution Process KCM Faêda, TA Pedrosa, NM Cantagalli, FS Lameiras, WB Ferraz Journal of Energy and Power Engineering 8 (9) , 2014 2014
Comminution of the U-10Mo by hydriding cycles innovative process K Faeda, AMM Santos, JB Paula, EM Pereira, TA Pedrosa, FS Lameiras, ... Associacao Brasileira de Energia Nuclear (ABEN), Rio de Janeiro, RJ (Brazil) , 2013 2013
Obtention of uranium-molybdenum alloy ingots technique to avoid carbon contamination TA Pedrosa, JB Paula, SC Reis, JGM Brina, KCM Faeda, WB Ferraz Associacao Brasileira de Energia Nuclear, Rio de Janeiro, RJ (Brazil) , 2011 2011
THE EVALUATION OF FLOW IRREGULARITIES IN THE AXISYMMETRIC DRAWING OF BARS THROUGH THE FINITE ELEMENT METHOD TA Pedrosa, AEM Pertence, HB Campos, PR Cetlin 61 DG Congresso Anual da Associacao Brasileira de Metalurgia e Materiais: 61 … , 2006 2006
THE COMPARISON OF NUMERICAL AND EXPERIMENTAL RESULTS FOR BULGING AND CONVERGENCE IN THE DRAWING OF CYLINDRICAL BARS TA Pedrosa, AE de Melo Pertence, HB Campos, PR Cetlin 60 DG Congresso Anual da Associacao Brasileira de Metalurgia e Materiais: 60 … , 2005 2005
