摘要:

The structure, magnetic properties and polar Kerr effects ofFe100−xSix(0⩽x⩽70)alloy films prepared by ion-beam co-sputtering were studied. We find that the saturation magnetization of these films decreases with increasingx,and a plateau of constant magnetization occurs as22⩽x⩽28.Their polar Kerr rotation&thgr;kdecreases with increasingxasx⩽16.2andx⩾30,but increases with increasingxas20⩽x⩽28.In the measuring wavelength range of 400–800 nm, the&thgr;kofFe72Si28film is 40&percent; to 50&percent; larger than that of pure Fe film. We think that amorphization may play an important role in enlarging the polar Kerr rotation of these films. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121062

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The number of passes of high-energy electrons through multiple foil and crystal radiators mounted inside of the Tomsk “Sirius” synchrotron, and the resulting increase in x-ray production efficiencies from these radiators, have been measured. The influence of electron transmission on the spectral and spatial distributions of parametric x radiation and on the spatial distribution of transition radiation has also been observed. We find that multiple passes increase the yields of these sources without destroying their angular distributions and spectra. Thus, multiple passes of electrons through these novel radiators may make them useful as x-ray sources for scientific and industrial purposes. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121063

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

A dual-axis atomic force microscope (AFM) cantilever with independent piezoresistive sensors has been developed for simultaneous detection of vertical and lateral forces. The cantilever consists of a flat, triangular probe connected to a base by four tall, narrow ribs. The vertically compliant triangular probe and the laterally compliant ribs incorporate separate piezoresistors for vertical and lateral force sensing. In the fabrication process, a special oblique ion implant technique is used to produce electrical elements on vertical sidewalls and horizontal surfaces of the cantilever structure at the same time. The dual-axis cantilever has been used to perform microfriction measurements as well as obtain simultaneous vertical-force and lateral-force AFM images. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121064

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Leakage current and dielectric breakdown behavior in annealedSiO2aerogel films for intermetal dielectric applications was investigated in a metal–insulator–semiconductor structure.SiO2aerogel films with porosities of 70&percent; exhibited Poole–Frenkel conduction both before and after annealing. After annealing at 450 and 700 °C, the leakage current density improved over the current range of the applied field. This behavior was characterized by different chemical evolutions in each annealing step, beginning with the removal of residual organics up to 450 °C and then with the removal of residual surface hydroxyl, along with subsequent microstructural changes, up to 700 °C. Except in the few initial failure modes, intrinsic dielectric breakdown was not observed up to 1 MV/cm for as-deposited or 450 °C annealed films. However, in the case of the 700 °C annealed film, the dielectric breakdown strength was degraded. It was inferred that this early breakdown in 700 °C annealed film was caused by a randomly enhanced electric field at the irregular asperity of the rough interface. This was confirmed by investigation of the interface roughness between the electrode and the film. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121065

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

BaTiO3/SrTiO3multilayered thin films were deposited on Si and Pt/Si substrates. X-ray diffraction clearly shows the formation of the superstructures. Phase transition properties were studied via dielectric measurements. Glassy behavior, characterized by a strong frequency dispersion of dielectric properties, was found in samples with a total thickness of 400 nm, while in samples with a total thickness of 800 nm, normal ferroelectric phase transitions with two dielectric peaks were observed. A preliminary interpretation assumes that size effects which frustrate long range ferroelectric ordering may lead to the relaxational behavior inBaTiO3/SrTiO3superstructures. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121066

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

This letter presents micromachined two-dimensional array flextensional transducers that can be used to generate sound in air or water. Individual array elements consist of a thin piezoelectric ring and a thin, fully supported, circular membrane. We report on an optimum design for an individual array element based on finite element modeling. We manufacture the transducer in two-dimensional arrays using planar silicon micromachining and demonstrate ultrasound transmission in air at 2.85 MHz. Such an array could be combined with on-board driving and an addressing circuitry for different applications. ©1998 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.121067

出版商:AIP    

年代:1998

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.121061

出版商:AIP    

年代:1998

数据来源: AIP