摘要:

Schottky contacts of Al/Si1−x−yGexCywere fabricated using conventional Si technology. Effects of thermal processing of the alloys on the electrical properties of the Al/Si1−x−yGexCySchottky diodes were investigated. Current–voltage (I–V), capacitance–voltage (C–V), and x‐ray diffraction measurements were performed. These thick alloy films (100–150 nm) experienced strain relaxation upon annealing at 700 °C. Nearly idealI–VandC–Vbehaviors were obtained for strain‐compensated samples.I–VandC–Vcharacteristics show evidence of dislocation‐related traps for strain‐relaxed samples. Carbon incorporation improves theI–VandC–Vcharacteristics by lessening the extent of lattice relaxation due to thermal processing. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117208

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

A new method to prepare bicrystals with well defined planar interfaces in YBa2Cu3Ox(Y123) has been developed. The bicrystal misorientation is controlled by dual seeding using Nd1+xBa2−xCu3Oysingle crystals. The grain boundary plane orientation is influenced by the positioning of the seeds and by control of the temperature gradient. The macro‐, meso‐, and microscopic planarity of the grain boundaries has been established by optical and electron microscopy. In addition, a difference in critical current density between the low (≤10°) and the high (≥20°) misorientation angle regime of nearly two orders of magnitude has been established in a series of [001]‐tilt grain boundaries. Thus, this type of grain boundary may allow a less ambiguous interpretation of the relationship between microstructure and transport properties than is possible from bicrystal thin film boundaries by eliminating the potential variations in properties associated with a varying grain boundary plane. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117209

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Oscillations are shown to exist in the inversion symmetry of the electronic wave function of a hydrogenic atom coherently excited to a Rydberg state by a short pulse of laser radiation in a uniform electric field. The dependence of these oscillations on field strength is shown to scale asn2wherenis the principal quantum number. The possibility of using these oscillations to measure electric signals on picosecond timescales (terahertz frequencies) is suggested. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117180

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Nanometer‐scale recording on an organic‐complex thin film with a scanning tunneling microscope (STM) under ambient conditions is demonstrated. The recording marks are made by applying external voltage pulses between the tip and the highly ordered pyrolytic graphite substrate. A 30×30 nm2STM image with recorded marks is given. The average recorded mark is 1.3 nm in diameter, which corresponds to a data storage density of about 1013bits/cm2. The current–voltage characteristics measured by the STM show an insulator behavior for the unrecorded regions, and a conductor behavior for the recorded regions, which indicates that the data are recorded by local change of the electrical property of the films. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117181

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The stresses in the aluminum oxide formed during high‐temperature oxidation of a bond‐coated superalloy are shown to be measurable through zirconia thermal barrier coatings. The basis for the measurements is the piezospectroscopic shift in theR‐line fluorescence (photoluminescence) from Cr3+impurities incorporated into the growing aluminum oxide scale. Measurements through the thermal barrier coating are feasible because (partially stabilized) zirconia coatings have some transparency at both the excitation and at fluorescence frequencies. ©1996 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.117182

出版商:AIP    

年代:1996

数据来源: AIP