GIL GONZÁLEZ , Eva

óxido mixto de hierro y bismuto, BiFeO3, con estructura tipo perovskita, es uno de los materiales magnetoeléctricos más estudiados, ya que a temperatura ambiente presenta simultáneamente propiedades ferroeléctricas y antiferromagnéticas. A pesar de su versatilidad y alto potencial de uso como electrocerámica, su implementación se ve frenada por...

Este Ciclo de Mejora en el Aula (CIMA) se ha aplicado a las prácticas de laboratorio de la asignatura de Química General del primer curso de Ingeniería Química Industrial. Se describe de manera detallada el mapa de contenidos, el modelo metodológico posible y la secuencia de actividades propuestas, de tal forma que la experimentación en el...

Flash Sintering (FS), a relatively new Field-Assisted Sintering Technique (FAST) for ceramic processing, was proposed for the first time in 2010 by Prof. Rishi Raj's group from the University of Colorado at Boulder. It quickly grabbed the attention of the scientific community and since then, the field has rapidly evolved, constituting a true...

Parametrization of mechanochemical reactions, or relating the evolution of the reaction progress to the supplied input power, is required both to establish protocols and to gain insight into mechanochemical reactions. Thus, results could be compared, replicated, or scaled up even under different milling conditions, enlarging the domains of...

Samples in the system Bi1−xYbxFeO3 (0.02 ≤ × ≤ 0.07) have for the first time been prepared by mechanical activation followed by sintering. XRD and DSC measurements show that the solubility limit of ytterbium in the R3c Bi1−xYbxFeO3 system is reached at x∼0.03. Higher ytterbium contents lead to a two-phase mixture of a main R3c phase of...

Bi2Fe4O9 was prepared by solid-state reaction and the electrical properties measured by impedance spectro- scopy. After annealing in O2 at 900 °C, Bi2Fe4O9 is an electrically-homogeneous insulator. Its high frequency permittivity is constant (∼14.1) over the temperature range 300–400 °C and shows no evidence of incipient ferroelectricity at...

The thermal degradation kinetics of several ethylene-propylene copolymers (EPM) and ethylene-propylene-diene terpolymers (EPDM), with different chemical compositions, have been studied by means of the combined kinetic analysis. Until now, attempts to establish the kinetic model for the process have been unsuccessful and previous reports suggest...

We show that BiFeO, that is electrically homogeneous, is a good insulator, and has a low dielectric constant (the properties desired in its applications), can be produced by flash sintering, which is nominally difficult to achieve by conventional and spark plasma sintering processes. The flash-sintered specimens had a uniform microstructure...

Mechanochemistry has attracted a lot of attention over the last few decades with a rapid growth in the number of publications due to its unique features. However, very little is known about how mechanical energy is converted into chemical energy. Most of the published works using mechanochemistry neglect the required attention to the...

Low temperature magnetic properties of BiFeO₃ powders sintered by flash and spark plasma sintering were studied. An anomaly observed in the magnetic measurements at 250 K proves the clear existence of a phase transition. This transformation, which becomes less well-defined as the grain sizes are reduced to nanometer scale, was described with...

Mixed powders of Bi2O3 and Fe2O3 are shown to yield single-phase, dense nanostructured polycrystals of BiFeO3 in reaction flash sintering experiments, carried out by applying a field of 50 V cm 1 and with the current limit set to 35 mA mm 2 . The furnace was heated at a constant rate with the reaction sintering taking place abruptly upon...