摘要:

A flash evaporation technique was developed for the production of high purity, unfractioned Permalloy films. A high boat temperature was found to be necessary to prevent fractionation of the nickel and iron in the production of the vertically deposited films. Low water vapor content was also found to be necessary in the residual gas of the vacuum system to prevent the refractory metal of the boat from appearing in the deposited film.

ISSN:0034-6748    

DOI:10.1063/1.1685334

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A 127° electrostatic cylindrical analyzer has been adapted for photoemission measurements. The resolution of the unit is 1.3% at 20 eV, increasing to 3.5% at 2 eV. The transmission is about 9% for energies higher than 6 eV. Integral photocurrents down to 10−15A can be analyzed with a signal‐to‐noise ratio of 100. Digital data acquisition allows differentiation of the measured energy distribution spectra to enhance structure. The result is equivalent to an ac modulation technique with a considerable improvement in signal‐to‐noise ratio for a given integration time. Data on platinum are used as an example.

ISSN:0034-6748    

DOI:10.1063/1.1685335

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A compact electrically pulsed HF laser is being described. The laser operates on a mixture of SF6and H2with 0.06 J energy, 25 kV pulses with a repetition of 100 pulses/sec. The output consists of theP(1)–P(7) rotational lines of the 1–0 vibrational transition and theP(2)–P(9) lines of the 2–1 transition. Line selection is provided by using a plane 300 line/mm grating as one reflector; the other reflector is an Irtran 4 flat used as a semitransparent mirror. Average power in all lines is 20 mW. Peak pulse power in individual lines is 15–20 W. Average and pulse power show good stability. The laser provides a convenient and compact source of ir radiation in the 2.5–3.0 &mgr; region.

ISSN:0034-6748    

DOI:10.1063/1.1685336

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

Details of an improved ion thinning apparatus, suitable for preparing electron microscope foils of inorganic nonmetallic samples (ceramics, minerals, rocks), are described, along with a resume of conditions for its optimum operation. Problems of surface topography and radiation damage associated with the ion thinning process are also briefly discussed.

ISSN:0034-6748    

DOI:10.1063/1.1685337

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A twin tube flash x‐ray unit is used to probe the density of expanding metal vapor produced in exploding wire experiments. Using an axial orientation for one of the tubes, details not seen in usual perpendicular pictures can be brought out. The developed x‐ray film is scanned by a microphotometer and the trace compared with a standard wedge exposed on the same film. The tracings are then reduced to obtain density as a function of radius. Typical results as applied to copper wire are included.

ISSN:0034-6748    

DOI:10.1063/1.1685338

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A technique is described for the electrical discharge machining of prolate spheroid specimens from metallic rods using conventionally milled electrodes. Specimens of Nb, Ta, Re, and Nb&sngbnd;Ta alloys have been satisfactorily prepared. For single crystals of Nb, x‐ray studies indicate the absence of any recrystallization after heat treatment of the prolate spheriods to remove strains.

ISSN:0034-6748    

DOI:10.1063/1.1685339

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A device is described which allows precise bending of crystal slabs by means of four rods, for use in x‐ray spectrometers. The crystal slabs can be bent into a curved cylindrical form having the curvature of a circle or of a logarithmic spiral, the latter giving ideal focusing for one wavelength.

ISSN:0034-6748    

DOI:10.1063/1.1685340

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A crystal cleaver and electron analyzer assembly is presented which allows good reproducibility of energy distribution curves of photoelectrons emitted from 10−11Torr cleaved single crystals. The analyzer resolution is shown to be better than 50 meV for electron kinetic energy up to 2.5 eV. Additional facilities include crystal temperature control between −100 and +150°C.

ISSN:0034-6748    

DOI:10.1063/1.1685341

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A new system suitable for studies of matrix isolated metal atoms is described and evaluated. The system incorporates a closed cycle helium refrigerator used to cool the sample block down to, or slightly below, 20 K and an electron beam sublimator to produce atomic beams of most of the refractory metals. The advantages of the system are its compactness and ease of operation.

ISSN:0034-6748    

DOI:10.1063/1.1685342

出版商:AIP    

年代:1971

数据来源: AIP

摘要:

A circuit is described which employs an operational amplifier arranged as a voltage follower to obtain output impedances as low as 0.001 &OHgr;. Direct drift and noise levels are such that the circuit can be used as both a dc and ac voltage source for tunnel junction measurements. A comparison is made with a similar ac conductance bridge recently reported in the literature and a simple modification of the latter circuit is suggested.

ISSN:0034-6748    

DOI:10.1063/1.1685343

出版商:AIP    

年代:1971

数据来源: AIP