摘要:

The ionic transference number of rf‐sputtered calcia‐stabilized zirconia (CSZ) thin films has been investigated, using the Nernst method, in the 300 °–400 °C temperature range and between 10−4and 2×10−1atm of oxygen partial pressure. E.M.F. measurements at 342 °C on Ni–NiO/CSZ/Pt–O2galvanic cells show a voltage roughly 5% lower than the theoretical value and an ionic transference number of about 0.85. Possibilities of such cells being used as oxygen sensors were estimated. Rise times typically observed between 10−3and 10−2atm of oxygen were approximately 4 min at 280 °C and 5 s at 420 °C. The influence of Pt deposition parameters on the response speed is pointed out.

ISSN:0022-5355    

DOI:10.1116/1.569266

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

Profiles of sputter‐deposited films using a mask were measured and compared to theoretical profiles. A discontinuity in the slope of the film profile is shown to be due to the finite thickness of the mask. Backscattering in rf sputter etching is shown to cause two effects: an apparent enhanced etching rate near the mask edge and nonvertical edges of the etched groove. Significant improvement in the etching profile was obtained by using slow‐etching electrodes and low gas pressures.

ISSN:0022-5355    

DOI:10.1116/1.569267

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

The slow adsorption of propane on aluminum has been observed using SIMS. The adsorbed hydrocarbon species give rise to a characteristic ’’cracking pattern’’ in the mass spectrum. The main ion peaks resulting are C3H8 +, C3H7 +, C3H5 +, C3H3 +, C2H5 +, and CH3 +. The hydrocarbon ions have very low energies. Electron‐induced desorption of hydrocarbon ions was also observed, but in this case the cross sections for ionic desorption were very small.

ISSN:0022-5355    

DOI:10.1116/1.569268

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

Photoemission measurements were taken in indium phosphide from the band gap to 1.8 eV photon energies. The surface activation procedure using cesium and oxygen is described. The condition of the surface was monitored for its crystallinity by a low‐energy‐electron‐diffraction (LEED) camera, and for its purity by Auger electron spectroscopy. The work functions were measured by the electron beam retarding potential method to determine the consequence of the activation processes. The result of the LEED analyses and the work‐function measurements indicate that the activation takes place on the surface in a patchy form. The results of the photoemission data are analyzed in light of the three‐step diffusion model photoemission theory. From the data of the photoemission, the bulk diffusion length is determined to be 530 nm and the surface escape probability to be less than 0.025. Correlating the results of the photoemission experiments with LEED and work‐function measurements, it is found that the surface of indium phosphide is not stable when it is activated, i.e., the photoemission slowly changed. An estimate of the thermalization length is derived and the value is used to describe the discrepancy between the diffusion model theory and the experimental results at photon energies higher than 1.5 eV.

ISSN:0022-5355    

DOI:10.1116/1.569269

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

A model of the evaporation kinetics of pure selenium from a large‐area boat of complex geometry is presented. The model includes conductive and evaporative heat‐transfer components in the liquid, accounts for the constantly decreasing liquid‐pool height, and demonstrates that natural convection effects are unimportant. A good fit to the experimental data is obtained over most of the range except at the tail end of the evaporation, where small inclinations of the boat from the horizontal have large effects. The utility of the model lies in its ability to predict the evaporation kinetics when changes are made in such operating parameters as the heating rate or boat loading.

ISSN:0022-5355    

DOI:10.1116/1.569270

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

The problem of knowing the exact temperature of a radiatively heated substrate has been recognized for some time. The present paper reports direct measurements which quantify the types of errors introduced into thermocouple readings (due to the radiation field); it also demonstrates the extent of temperature variations when the substrate and radiant heater are large and of comparable size, and not in intimate and uniform contact. Thermocouples can be used only if their contact to the substrate is intimate (e.g., welded), if they traverse minimum distance in the radiation field (through the heater to the substrate), and if they are protected by their own radiation shield.

ISSN:0022-5355    

DOI:10.1116/1.569271

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

A program to recycle Ti–6Al–4V machine chip scrap by electron‐beam (EB) melting is described. The advantages of utilizing EB melting are described in terms of the selection of raw materials, the unique characteristics of the EB hearth furnace, the alloying and refining reactions that are promoted, and the unique character of the solidification process. Experimental results are presented on a manufacturing technology program sponsored by the Air Force Materials Laboratory in which machined chips, sponge, and alloy elements are recycled into specification grade Ti–6Al–4V bar stock.

ISSN:0022-5355    

DOI:10.1116/1.569272

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

摘要:

The performance and features of ring gap discharges are described. A limited plasma of high density in the cathode region as well as magnetic and electrostatic focusing of the electrons on a given directrix are characteristic of this discharge type. In conformity with the shape of this curve, various ring gap discharges of different geometry can be put into being, e.g., planar type and torus type, just to cite an example. Based on ring gap discharges several ion‐aided technologies may thus be used to advantage in the field of vacuum deposition. High‐rate sputtering, for instance, permits deposition rates in the order of some micrometers per minute which, in turn, brought about entirely new coating arrangements. Against sputter cleaning in a glow discharge the energetic efficiency of substrate pretreatment is about seven times as high and the cleaning speed increases by approximately two orders of magnitude. Alternating ion plating results in very high ion rates. With plasma plating, on the other hand, a single energy source is sufficient to generate on the substrate a powerful stream of vapor particles, sputtered particles, and ions.

ISSN:0022-5355    

DOI:10.1116/1.569273

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

ISSN:0022-5355    

DOI:10.1116/1.569274

出版商:American Vacuum Society    

年代:1977

数据来源: AIP

ISSN:0022-5355    

DOI:10.1116/1.569275

出版商:American Vacuum Society    

年代:1977

数据来源: AIP