			Home About us Contact

Driving Field (driving + field)

Distribution by Scientific Domains

Polymers and Materials Science	50%
Physics and Astronomy	50%

Selected Abstracts

Temperature-Insensitive Large Strain of (Bi1/2Na1/2)TiO3,(Bi1/2K1/2)TiO3,(K0.5Na0.5)NbO3 Lead-Free Piezoceramics

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2010
Klaus T. P. Seifert
The effect of (K0.5Na0.5)NbO3 (KNN) addition on the ferroelectric behavior of (Bi1/2Na1/2)TiO3,(Bi1/2K1/2)TiO3 (BNT,BKT) lead-free piezoceramics was investigated. Polarization and strain hysteresis loops indicate that the ferroelectric order is disrupted significantly with the addition of KNN as a replacement for BNT and the destabilization of the ferroelectric order is accompanied by an enhancement of the unipolar strain, which peaks at a value of ,0.48% (corresponding to a large signal d33 of ,600 pm/V) at 1 mol% KNN content. This strain was analyzed as derived from an electrostrictive effect at lower electric fields and a converse piezoelectric effect at higher electric fields. By limiting the electric driving field to exclude the contribution from the converse piezoelectric effect, a temperature-insensitive large-field d33 of ,250 pm/V up to 200°C was achieved. [source]

Monte Carlo study of 2D electron gas transport including Pauli exclusion principle in highly doped silicon

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2008
F. Carosella
Abstract A Multi Sub-band Monte Carlo Simulator improved to efficiently include the Pauli Exclusion Principle is presented. It is used to study the transport in highly doped and ultra-thin silicon film. Both steady state and transient regime of transport for silicon films under uniform driving field are investigated. Such approach aims to be carried out in a full device simulator to improve the modeling of the access region of nano-Double Gate MOSFETs. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Towards high-fidelity two-photon quantum communications

FORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 4-5 2003
G. Kurizki
We propose two alternative scheme for highly efficient nonlinear interaction between weak optical fields. The first scheme is based on the attainment of electromagnetically induced transparency simultaneously for two fields via transitions between magnetically split F = 1 atomic sublevels, in the presence of two driving fields. The second scheme relies on simultaneous electromagnetically- and self-induced transparencies of the two fields. Thereby, equal slow group velocities and giant cross-phase modulation of the weak fields over long distances are achieved. [source]

Silicone,Poly(hexylthiophene) Blends as Elastomers with Enhanced Electromechanical Transduction Properties,

ADVANCED FUNCTIONAL MATERIALS, Issue 2 2008
F. Carpi
Abstract Dielectric elastomers are progressively emerging as one of the best-performing classes of electroactive polymers for electromechanical transduction. They are used for actuation devices driven by the so-called Maxwell stress effect. At present, the need for high-driving electric fields limits the use of these transduction materials in some areas of potential application, especially in the case of biomedical disciplines. A reduction of the driving fields may be achieved with new elastomers offering intrinsically superior electromechanical properties. So far, most attempts in this direction have been focused on the development of composites between elastomer matrixes and high-permittivity ceramic fillers, yielding limited results. In this work, a different approach was adopted for increasing the electromechanical response of a common type of dielectric elastomer. The technique consisted in blending, rather than loading, the elastomer (poly(dimethylsiloxane)) with a highly polarizable conjugated polymer (undoped poly(3-hexylthiophene)). The resulting material was characterised by dielectric spectroscopy, scanning electron microscopy, tensile mechanical analysis, and electromechanical transduction tests. Very low percentages (1,6 wt %) of poly(3-hexylthiophene) yielded both an increase of the relative dielectric permittivity and an unexpected reduction of the tensile elastic modulus. Both these factors synergetically contributed to a remarkable increase of the electromechanical response, which reached a maximum at 1 wt % content of conjugated polymer. Estimations based on a simple linear model were compared with the experimental electromechanical data and a good agreement was found up to 1 wt %. This approach may lead to the development of new types of materials suitable for several types of applications requiring elastomers with improved electromechanical properties. [source]