Encontrados 6 documentos, a visualizar página 1 de 1
Magnetic ordering above room temperature in the sigma-phase of Fe66V34
Cieslak, Jakub; Costa, Benilde F.O.; Dubiel, Stanislaw M.; Reissner, Michael; Steiner, Walterhttp://www.sciencedirect.com/science/article/B6TJJ-4VDY859-3/2/bf157132c7bb6e6d8959b06c268b0533
Synthesis, structure and magnetic behaviour of mixed metal leucophosphite
Shi, Fa-Nian; Santos, António Moreira dos; Cunha-Silva, Luís; Costa, Benilde F.O.; Klinowski, Jacek; Paz, Filipe A. Almeida; Amaral, Vítor S.A synthetic analogue of leucophosphite, an iron phosphate, was synthesized hydrothermally at 180 °C and its chemical composition determined to be K[(FeV)(PO4)2(OH)(H2O)]·H2O. The compound crystallizes in the monoclinic P21/c space group, with a=9.7210(19) Å, b=9.6500(19) Å, c=12.198(4) Å and [beta]=128.569(18)°. While the original all-iron compound is reported to be antiferromagnetic, the inclusion of substitut...
Fe2O3/aluminum thermite reaction intermediate and final products characterization
Durães, Luísa; Costa, Benilde F.O.; Santos, Regina; Correia, António; Campos, José; Portugal, AntónioRadial combustion experiments on Fe2O3/aluminum thermite thin circular samples were conducted. A stoichiometric (Fe2O3 + 2Al) and four over aluminized mixtures were tested. The combustion products were characterized by X-ray diffraction and Mössbauer spectroscopy and the influence of Fe2O3/aluminum ratio on their composition was assessed. The main products were identified as alumina ([alpha]-Al2O3) and iron (Fe...
In Situ Synthesis of Magnetite Nanoparticles in Carrageenan Gels
Daniel-da-Silva, Ana L.; Trindade, T.; Goodfellow, Brian J.; Costa, Benilde F. O.; Correia, Rui N.; Gil, Ana M.Magnetite nanoparticles have been successfully synthesized in the presence of carrageenan polysaccharides using an in situ coprecipitation method. Iron coordination to the sulfate groups of the polysaccharide was confirmed by FTIR. The polysaccharide type (κ, ι, or λ) and concentration have been varied and their effects on particle morphology and chemical stability of the resultant nanocomposite investigated. T...
In situ synthesis of magnetite nanoparticles in carrageenan gels
Daniel-da-Silva, Ana. L.; Trindade, T.; Goodfellow, Brian J.; Costa, Benilde F. O.; Correia, Rui N.; Gil, Ana M.Magnetite nanoparticles have been successfully synthesized in the presence of carrageenan polysaccharides using an in situ coprecipitation method. Iron coordination to the sulfate groups of the polysaccharide was confirmed by FTIR. The polysaccharide type ( , é, or ì) and concentration have been varied and their effects on particle morphology and chemical stability of the resultant nanocomposite investigated. T...
Crystal structure of hydrated diphenylguanidinium hexafluoroferrate (III)
Silva, Manuela Ramos; Beja, Ana Matos; Costa, Benilde F. O.; Paixão, José A.; Veiga, Luiz Alte daThe crystal structure of 3C13H14N3+FeF63-·3.5H2O was determined. Both phenyl rings of the diphenylguanidine cation are oriented syn to the central C=NH2 group. The anions and cations are held together by a three-dimensional network of hydrogen bonds. In the synthesis of this compound, a second phase (iron trifluoride trihydrate) was formed and identified by powder diffraction data. Mössbauer results show two di...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||