Exploració per autor "Levit Valenzuela, Rafael"
Ara es mostren els items 1-10 de 10
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Comparative dielectric and thermally stimulated-depolarization-current studies of the liquid crystal dimers 1¿,9¿-bis(4-cyanobiphenyl-4'-yl) nonane and heptane and a binary mixture between them, close to the glass transition
Sellarès González, Jordi; Diego Vives, José Antonio; López Pérez, David Orencio; Salud Puig, Josep; Robles Hernández, Beatriz; de la Fuente Lavin, Maria Rosario; Cañadas Lorenzo, Juan Carlos; Mudarra López, Miguel; López de Rioja, Víctor; Levit Valenzuela, Rafael; Díez Berart, Sergio (American Institute of Physics (AIP), 2022-11-21)
Article
Accés obertWe have performed dielectric spectroscopy and thermally stimulated-depolarization-current experiments to study the molecular dynamics of the twist-bend nematic phase close to the glass transition of two members of the ... -
Determinación del polimorfismo del Br4C y aplicación en el análisis termodinámico en sistemas binarios
Levit Valenzuela, Rafael (Universitat Politècnica de Catalunya, 2007-09)
Projecte/Treball Final de Carrera
Accés obertEl principal objeto del presente trabajo es la determinación del diagrama Presión- Volumen-Temperatura del tetrabromuro de carbono mediante un dilatómetro en presión y la determinación experimental del diagrama de fases ... -
DNMR measurements of an asymmetric odd liquid crystal dimer: determination of the intramolecular angle and the degree of order of the two rigid cores
Sebastian Ugarteche, Nerea; Zupancic, Blaz; López Pérez, David Orencio; Salud Puig, Josep; López de Rioja, Víctor; Levit Valenzuela, Rafael; de la Fuente Lavin, Maria Rosario; Ros Latienda, Maria Blanca; Díez Berart, Sergio; Robles Hernández, Beatriz (Royal Society of Chemistry (RSC), 2023)
Article
Accés obertIn this work, we present a Deuteron Nuclear Magnetic Resonance (DNMR) study of the non-symmetric odd liquid crystal dimer a-(4-cyanobiphenyl-4'-yloxy)-¿-(1-pyrenimine-benzylidene-4'-oxy) heptane (CBO7O.Py), formed by a ... -
Evidence for a dynamics crossover and its implication on the freezing temperature determination of relaxor ferroelectrics
Levit Valenzuela, Rafael; Ochoa Guerrero, Diego A.; Martínez García, Julio Cesar; García García, José Eduardo (Institute of Physics (IOP), 2019-09-27)
Article
Accés obertRelaxor ferroelectrics are characterized by a broadened and dispersive permittivity peak in their temperature-dependent dielectric spectra. Although several models have been proposed to explain the nature of these materials, ... -
Insight into the dynamics of low temperature dielectric relaxation of ordinary perovskite ferroelectrics
Levit Valenzuela, Rafael; Ochoa Guerrero, Diego A.; Martínez García, Julio Cesar; García García, José Eduardo (2017-11-10)
Article
Accés obertThe temperature dependence of the dielectric response of ordinary ferroelectric materials exhibits a frequency-independent anomalous peak as a manifestation of the ferroelectric to paraelectric phase transition. A second ... -
Low temperature dielectric relaxation in ordinary perovskite ferroelectrics: enlightenment from high-energy x-ray diffraction
Ochoa Guerrero, Diego A.; Levit Valenzuela, Rafael; Fancher, Christopher M.; Esteves, Giovanni; Jones, Jacob L.; García García, José Eduardo (2017-04-26)
Article
Accés obertOrdinary ferroelectrics exhibit a second order phase transition that is characterized by a sharp peak in the dielectric permittivity at a frequency-independent temperature. Furthermore, these materials show a low temperature ... -
Nuevas aproximaciones al estudio de la dinámica de la relajación dieléctrica en ferroeléctricos ordinarios y relajadores
Levit Valenzuela, Rafael (Universitat Politècnica de Catalunya, 2019-12-10)
Tesi
Accés obertFerroelectric materials are endowed with fascinating functional properties from the technological point of view. Consequently, they have promoted the design of ferroelectric-based devices with applications in a vast range ... -
Relationship between the two-component system 1-Br-adamantane + 1-Cl-adamantane and the high-pressure properties of the pure components
Barrio Casado, María del; Levit Valenzuela, Rafael; Lloveras Muntané, Pol Marcel; Aznar Luque, Araceli; Negrier, Philippe; Mondieig, Denise; Tamarit Mur, José Luis (2018-03-15)
Article
Accés obertThe temperature-composition phase diagram of the two-component system 1-Br-adamantane and 1-Cl-adamantane has been determined by means of thermal analysis techniques and X-ray powder diffraction from the low-temperature ... -
The generalized Vogel-Fulcher-Tamman equation for describing the dynamics of relaxor ferroelectrics
Levit Valenzuela, Rafael; Martínez García, Julio Cesar; Ochoa Guerrero, Diego A.; García García, José Eduardo (Nature, 2019-08-27)
Article
Accés obertRelaxor ferroelectrics (RF) are outstanding materials owing to their extraordinary dielectric, electromechanical, and electro-optical properties. Although their massive applications, they remain to be one of the most ... -
Unfolding kinetic fragility in relaxor ferroelectrics
Martínez García, Julio Cesar; Levit Valenzuela, Rafael; Ochoa Guerrero, Diego A.; García García, José Eduardo (American Institute of Physics (AIP), 2021-10-07)
Article
Accés obertThe fragility parameter is one of the most important material constants that is extensively used in glass science, playing a central role in the enhancement of the understanding the glass formation process of disordered ...