Relation between toughness, infinite fatigue life and microstructure in large blooms for automotive plastic molds.

Presentazione orale al European Congress on Advanced Material and Processes (Euromat 2005), Praga (R. Ceca), 5/10/2005 - 8/10/200

Voltage control of magnetic single domains in Ni discs on ferroelectric BaTiO<inf>3</inf>

For 1 μm diameter Ni discs on a BaTiO3 substrate, the local magnetization direction is determined by ferroelectric domain orientation as a consequence of growth strain, such that single domain discs lie on single ferroelectric domains. On applying a voltage across the substrate, ferroelectric domain switching yields non volatile magnetization rotations of 90°, while piezoelectric effects that are small and continuous yield non volatile magnetization reversals that are non-deterministic. This demonstration of magnetization reversal without ferroelectric domain switching implies reduced fatigue, and therefore represents a step towards applications

Voltage-driven displacement of magnetic vortex cores

Abstract Magnetic vortex cores in polycrystalline Ni discs underwent non-volatile displacements due to voltage-driven ferroelectric domain switching in single-crystal BaTiO3. This behaviour was observed using photoemission electron microscopy to image both the ferromagnetism and ferroelectricity, while varying in-plane sample orientation. The resulting vector maps of disc magnetization match well with micromagnetic simulations, which show that the vortex core is translated by the transit of a ferroelectric domain wall, and thus the inhomogeneous strain with which it is associated. The non-volatility is attributed to pinning inside the discs. Voltage-driven displacement of magnetic vortex cores is novel, and opens the way for studying voltage-driven vortex dynamics.The Royal Society, Gates Cambridge, the Winton Programme for the Physics of Sustainability, Trinity College (Cambridge), Agència de Gestió d’Ajuts Universitaris i de Recerca (AGAUR) from the Catalan governmen

Voltage-driven annihilation and creation of magnetic vortices in Ni discs.

Using photoemission electron microscopy (PEEM) to image ferromagnetism in polycrystalline Ni disks, and ferroelectricity in their single-crystal BaTiO3 substrates, we find that voltage-driven 90° ferroelectric domain switching serves to reversibly annihilate each magnetic vortex via uniaxial compressive strain, and that the orientation of the resulting bi-domain reveals the chirality of the annihilated vortex. Micromagnetic simulations reveal that only 60% of this strain is required for annihilation. Voltage control of magnetic vortices is novel, and should be energetically favourable with respect to the use of a magnetic field or an electrical current. In future, stray field from bi-domains could be exploited to read vortex chirality. Given that core polarity can already be read via stray field, our work represents a step towards four-state low-power memory applications.The Royal Society, Gates Cambridge, the Winton Programme for the Physics of Sustainability, Trinity College, Agència de Gestió d’Ajuts Universitaris i de Recerca (AGAUR) from the Catalan government for Beatriu de Pinós postdoctoral fellowship (2014 BP-A 00079)

Voltage-driven displacement of magnetic vortex cores

Magnetic vortex cores in polycrystalline Ni discs underwent non-volatile displacements due to voltage-driven ferroelectric domain switching in single-crystal BaTiO3. This behaviour was observed using photoemission electron microscopy to image both the ferromagnetism and ferroelectricity, while varying in-plane sample orientation. The resulting vector maps of disc magnetization match well with micromagnetic simulations, which show that the vortex core is translated by the transit of a ferroelectric domain wall, and thus the inhomogeneous strain with which it is associated. The non-volatility is attributed to pinning inside the discs. Voltage-driven displacement of magnetic vortex cores is novel, and opens the way for studying voltage-driven vortex dynamics

Relationships between tensile and fracture mechanics properties and fatigue properties of large plastic mold steel

presentazione oral

Centrality dependence of the expansion dynamics in Pb-Pb collisions at 158 A GeV/c

Two-particle correlation functions of negatively charged hadrons from Pb-Pb collisions at 158 GeV/c per nucleon have been measured by the WA97 experiment at the CERN SPS. A Coulomb correction procedure that assumes an expanding source has been implemented. Within the framework of an expanding thermalized source model the size and dynamical state of the collision fireball at freeze-out have been reconstructed as a function of the centrality of the collision. Less central collisions exhibit a different dynamics than central ones: both transverse and longitudinal expansion velocities are slower, the expansion duration is shorter and the system freezes out showing smaller dimensions and higher temperature.Comment: 22 pages, 11 figures, Te

correlation between clinic pathological features msi pd l1 and survival in resectable gastric cancer looking for prognostic biomarkers

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Effects of microalloying on an innovative quenched and tempered plastic mold steel

presentazione orale al TMS 2008 Annual Meeting & Exhibition (TMS2008), New Orleans, LA, USA, 9/3/2008 - 13/3/200