摘要:

Measurements of the surface resistance of plane surfaces of single‐crystal copper carried out at 35 GHz indicate the existence of an anomalous skin effect at room temperature. The surfaces were prepared in stress‐free processes, annealed, and manipulated in purified hydrogen and argon.

ISSN:0021-8979    

DOI:10.1063/1.1663593

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The phase diagram of the Mn&sngbnd;Bi system near the compound MnBi was studied with single crystals in the as‐grown and heat‐treated states. The results show that the high‐temperature phase of MnBi is in fact a separate compound with chemical formula Mn1.08Bi, when grown from a Bi‐rich solution. It was found that the transformation of MnBi at 355°C upon heating is associated with a peritectic decomposition of MnBi into Mn1.08Bi+liquid, and the transformation at 340°C upon cooling of the high‐temperature phase is the result of decomposition of Mn1.08Bi to MnBi±Mn.

ISSN:0021-8979    

DOI:10.1063/1.1663594

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The room‐temperature internal friction of pure (99.989%) annealed polycrystalline aluminum has been studied as a function of fatigue and neutron irradiation. Fatigue was found to reduce the internal friction of unirradiated aluminum by more than 50% within the first 1% of the fatigue life. This effect is attributed to rapid strain hardening in the pure aluminum. Neutron irradiation causes a large reduction in internal friction, presumably because of dislocation pinning by irradiation‐generated vacancies. It appears that these are multiple vacancies or vacancy clusters that are relatively stable at room temperature. Fatigue causes the internal friction of irradiated aluminum to converge to the same value as unirradiated aluminum near the fatigue limit. This result indicates that irradiation‐generated vacancies may be readily absorbed by moving dislocations and explains the observation that the fatigue strength of aluminum is relatively unchanged by irradiation.

ISSN:0021-8979    

DOI:10.1063/1.1663595

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

A controversy exists over whether the nonimaging of the cobalt atoms in field ion images from ordered alloys of cobalt and platinum is due to their preferential evaporation or simply to their invisibility due to selective ionization. Recent atom probe results are held to support the latter theory. It is shown that these results have been misinterpreted and that they in fact support the former theory instead.

ISSN:0021-8979    

DOI:10.1063/1.1663596

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Southworth's critical comments on our interpretation of Pt3Co field ion images is rebutted by pointing out the fact that the top PtCo layers used in our atom probe experiment were completely resolved.

ISSN:0021-8979    

DOI:10.1063/1.1663597

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

Transmission electron microscope studies of the colloids of silver in KCl : Ag crystals show that the colloidal particles are spherical in shape and have a size distribution among them. Using the observed size distribution and modified optical constants for small metal particles by the Kawabata‐Kubo method and Mie's theory, the calculated shapes of the optical bands agree well with the observed band shape.

ISSN:0021-8979    

DOI:10.1063/1.1663598

出版商:AIP    

年代:1974

数据来源: AIP

摘要:

The Raman spectrum of glassy carbon has been measured. Two broad lines are observed at 1340 and 1590 cm−1. These results are consistent with the turbostratic structure, which has been suggested for glassy carbon, with a particle sizeLaof approximately 30 Å.

ISSN:0021-8979    

DOI:10.1063/1.1663599

出版商:AIP    

年代:1974

数据来源: AIP