摘要:

A new method is presented to measure in‐plane vibration amplitudes of the order of some 10 nm. The measurement system utilizes the speckle effect and consists of only a few mechanical components. The evaluation is done by a microcomputer. The whole system is insensitive to environmental noise. The method has been applied to investigate the amplitude distribution of plano‐convex AT‐cut quartz crystals as they are commonly used in thin‐film thickness monitors.

ISSN:0034-6748    

DOI:10.1063/1.1137765

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A general circuit design is described for the transient hot‐strip method which is presently used for studies of electrical properties of thin metal films and for measurements of thermal properties of insulating solids and liquids. It is demonstrated that a low driving voltage can be used for thin films having comparably high resistance, and that the output of power in the strip source (being the nonlinear component of the circuit) can be kept constant throughout the transient recording. The experimental arrangement for constant power conforms with the assumptions of the theory for the method and extends its validity to substantially larger temperature increases of the nonlinear resistance.

ISSN:0034-6748    

DOI:10.1063/1.1137766

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

An accurate resistiometric technique for measuring fast diffusion of hydrogen in metals is described. The sample is in the form of a foil having uniform cross section and a length much greater than its width. Samples are electrolytically loaded with hydrogen to about 0.5 atomic percent. Initially the hydrogen is held at uniform concentration in essentially half the length of the foil by the effect of a dc electrotransport current of 2500 A/cm2in the other half. After this current is removed, the diffusion of hydrogen into the second half is monitored by its effect on the resistance of a small section of the foil. With this technique a single sample may be reused to make many measurements of D. The measurement ofDis absolute, and use of a sensitive differential ac measurement yields results for low hydrogen concentrations.

ISSN:0034-6748    

DOI:10.1063/1.1137767

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A helium gas flow‐type cryostat was developed. The cryostat was designed for experiments in ultrahigh vacuum, especially for studies of adsorbed or condensed layers of gases on a crystal surface. The crystal surface was able to be kept at any temperature between 20 and 100 K. A temperature stability of 0.1 K was achieved by controlling the flow rate of cold helium gas.

ISSN:0034-6748    

DOI:10.1063/1.1137768

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Brief descriptions are given of 23 national facilities in the U. S. that are of importance to research in the physics of condensed matter. These facilities range from nuclear reactors and synchrotron sources to high‐voltage electron microscopes and facilities for the preparation of special materials and submicron structures. They take a variety of forms and are located in several kinds of institutions, but are alike in being available to qualified scientists from other laboratories. The primary purpose, size, major experimental equipment, and method of operation are described for each facility.

ISSN:0034-6748    

DOI:10.1063/1.1137769

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Using the inflection point method of interpreting emissive probes, it is shown that it is possible to measure the electric space potential established between two parallel metal plates in a vacuum.

ISSN:0034-6748    

DOI:10.1063/1.1137770

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Microelectronic devices consist of features whose sizes are nominally less than 1 &mgr;m. Features of the same size appear also on the x‐ray masks used for processing the devices. For nondestructive testing of various structures it is useful to replicate the mask or circuit using a polymer layer. The replica can then be checked in a scanning electron microscope (SEM) for faults or problems in processing. It was found that PVC replication could faithfully reproduce features as small as 0.25 &mgr;m.

ISSN:0034-6748    

DOI:10.1063/1.1137771

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A direct comparison of the performances of the time‐of‐flight (TOF) atom‐probe mass spectrometer in the linear and the energy‐compensated mode has been carried out using our newly constructed combined‐type TOF atom‐probe field ion microscope. The detectability and the mass resolution were measured using the W(011) plane and the Mo(011) plane, respectively. The results suggest that in the energy compensated‐type mass spectrometer, the use of an einzel lens for focusing the ion beam (called a ‘‘focusing energy compensated‐part’’ in the text) is an effective way to increase the transmittance of ions through the deflector system without lowering mass resolution. It is suggested that this type of TOF atom probe is the best.

ISSN:0034-6748    

DOI:10.1063/1.1137772

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A simple, low‐cost, and flexible personal computer‐based automatic measurement system used for deep‐level transient spectroscopy (DLTS) is developed and implemented. An IEEE‐488 interface bus is designated for communication between the personal computer and instruments. This configuration provides advantages in ease of operation and quick set up, especially for the purpose of data acquisition and processing. In general, the system can be applied to any programmable measurement automatic configuration. A linear least‐square regression method is used to process the Arrhenius plot and to determine the activation energy. The DLTS signal and the Arrhenius plot are plotted and displayed during one thermal scan. A new DLTS computation algorithm has also been employed.

ISSN:0034-6748    

DOI:10.1063/1.1137773

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

This diver‐portable instrument measures relative depths to a precision of ±0.02 m in real time by using two sensitive pressure sensors. It fulfills a need by diver scientists to measure relative water depths in any underwater current in which diving is possible, but without being encumbered by unwieldy equipment such as was used previously. Typical applications include the measurement of stratigraphic levels on sea‐bed sites of historical, biological, and geological interest.

ISSN:0034-6748    

DOI:10.1063/1.1137774

出版商:AIP    

年代:1984

数据来源: AIP