摘要:

The ac field dependence of dielectric response of sol-gel derivedPb(Zr, Ti)O3thin films is presented. The analysis of amplitude and phase angle of first and third harmonic of the polarization at subswitching fields shows that a description of the dielectric nonlinearity by the classical polynomial approximation is inadequate. A qualitatively better description of many features of the experimental data is obtained using the Rayleigh relationship, indicating that the nonlinear behavior is associated with the pinning of domain walls on randomly distributed pinning centers. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.122362

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The microgun is a combination of a nanotip and a microlens which is composed of two planar micron-size bore electrodes and a coplanar four-pole deflector microfabricated on the same Si chip. The focusing and deflection characteristics of the microgun, working as an immersion lens at 100 V, have been studied both experimentally and by numerical simulations. Results show unique electron optics properties due mainly to the coherence of the electron beam emitted from the nanotip and to the noninteraction of the incident electrons with the different microelectrodes. The focus spot can reach nanometric dimensions with minimum aberrations and a deflection amplitude of∼2.5 mrad/V.©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.122363

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

We define superconducting constrictions by ploughing a deposited Aluminum film with a scanning probe microscope. The microscope tip is modified by electron-beam deposition to form a nanoplough of diamond-like hardness which allows the definition of highly transparent Josephson junctions. Additionally, a dc superconducting quantum interference device is fabricated in order to verify the junction’s behavior. The devices are easily integrated in mesoscopic devices as local radiation sources and can be used as tunable on-chip millimeter-wave sources. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.122364

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

We report a large electrostrictive strain in electron irradiated poly(vinylidene fluoride–trifluoroethylene) copolymer at a composition with 65 mol &percent; vinylidene fluoride, which also exhibits a large ratio of strain to applied field (∼275 pm/V). The strain response is nearly independent of the external driving condition (unipolar or bipolar field) and does not change with temperature in about 20 °C temperature range near room temperature. Moreover, near room temperature, the material can reach a relatively high quasistatic longitudinal electromechanical coupling factork33∼0.33.©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.122365

出版商:AIP    

年代:1998

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.122561

出版商:AIP    

年代:1998

数据来源: AIP