排序方式: 共有37条查询结果,搜索用时 15 毫秒
31.
LeClair P Swagten HJ Kohlhepp JT van De Veerdonk RJ de Jonge WJ 《Physical review letters》2000,84(13):2933-2936
Co/Al2O3/Co magnetic tunnel junctions with an interfacial Cu layer have been investigated with in situ growth characterization and ex situ magnetotransport measurements. Cu interlayers grown on Co give an approximately exponential decay of the tunneling magnetoresistance with xi approximately 0.26 nm while those grown on Al2O3 have a decay length of 0.70 nm. The difference in decay lengths can be explained by different growth morphologies, and in this way clarifies a present disagreement in the literature. For monolayer coverage of Cu, we show that the tunneling spin polarization is suppressed by at least a factor of 2 compared to Co and beyond approximately 5 ML it becomes vanishingly small. 相似文献
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N. P. Hessey E. C. Booth W. J. Fickinger K. P. Gall M. D. Hasinoff D. Horváth J. Lowe E. K. McIntyre D. F. Measday J. P. Miller A. J. Noble B. L. Roberts D. K. Robinson M. Sakitt M. Salomon D. A. Whitehouse 《Zeitschrift fur Physik C Particles and Fields》1989,42(2):175-183
We have measured the weak radiative decay branching ratio (∑ + →pγ)/(∑ + →pπ0). The experiment was carried out at Brookhaven National Laboratory using a low-energy separatedK ? beam stopping in liquid hydrogen. The∑ + was tagged by observing the pion fromK ? K + p→∑ +π? in a range telescope, and the gamma was detected in a segmented NaI detector. The result is (2.81±0.39 ?0.43 +0.21 )×10?3, which is consistent with previous measurements. This corresponds to a branching ratio for (∑ + →pγ)/(∑ + → all) of (1.45±0.20 ?0.22 +0.11 )×10?3, where the quoted errors are statistical and systematic, respectively. A total of 408 signal events were observed, doubling the previous world total. 相似文献
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J. Bonn B. Bornschein L. Bornschein L. Fickinger B. Flatt A. Kovalik Ch. Kraus E. W. Otten J. P. Schall Th. Thümmler H. Ulrich Ch. Weinheimer 《Physics of Atomic Nuclei》2002,65(12):2171-2175
The presently lowest limit for the mass of the electron neutrino is m ν<2.2 eV/c 2 95% C.L.) derived from measurements at Mainz up to 1999. The data taken in 2000 are not fully analyzed yet, but limits of possible distortions as reported by the Troitsk group can be given. 相似文献
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R.L. Eisner W.J. Fickinger S.L. Glickman J.A. Malko J.F. Owens D.K. Robinson S. Dado A. Engler G.S. Keyes T. Kikuchi R.W. Kraemer 《Nuclear Physics B》1977,123(3):361-381
Results on K0 and Λ production in p↑p interactions at 6 GeV are presented. The data are from an exposure of the Argonne 12 ft bubble chamber to a 60% transversely polarized proton beam. Results include data on Λ and K0 inclusive production, and on the reactions p↑p → pΛK+(pΣ0K+). The beam asymmetry parameter for is determined to be (?0.52 ± 0.12). 相似文献
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The thickness and temperature dependences of the interlayer exchange coupling in well-defined molecular beam epitaxy-grown Fe/Si/Fe sandwich structures have been studied. The biquadratic coupling shows a strong temperature dependence in contrast to the bilinear coupling. Both depend exponentially on thickness. These observations can be well understood in the framework of Slonczewski's loose spins model [J. Appl. Phys. 73, 5957 (1993)]. No bilinear contribution of the loose spins to the coupling was observed. 相似文献