共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
Ayman El Tahan Gerhard Jakob Hermann Adrian Lucica Miu 《Physica C: Superconductivity and its Applications》2010,470(1):1-7
YBa2Cu3O7/PrBa2Cu3O7 (YBCO/PBCO) superlattices with a different ratio of the superconducting and insulating layer thicknesses were prepared by high pressure dc sputtering. The vortex-creep activation energy U0 was determined by analyzing the in-plane resistive transition of 200 μm wide bridges with the external magnetic field B oriented along the c axis. It was found that U0 is proportional to the thickness of the YBCO layers, and does only weakly depend on the PBCO layer thickness, when the latter exceeds two unit cells. We observed a change in the variation of U0 with the current I in the specimen: U0 exhibits a plateau in the low-I region, then decreases significantly with increasing I. This behaviour is explained in terms of a crossover plastic vortex creep – elastic (collective) creep induced by the transport current. 相似文献
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Epitaxial multilayers of YBa2Cu3O7-δ and P1Ba2Cu3O7-δ have been deposited on (100) cut SrTiO3 substrates using the technique of pulsed laser deposition. Standard ϑ-2ϑ X-ray diffraction measurements on the films showed excellent superlattice reflections. The mixed state of these superlattices
has been probed through measurements of radio frequency penetration depth (λ) as a function of temperature (T), magnetic field (H) and it’s orientation (ϑ) with respect to the planes of the superlattices. These data reflect the two-dimensional nature of the mixed state in these
systems. 相似文献
15.
16.
17.
18.
J. Niemeyer N. D. Kataria M. R. Dietrich C. Politis H. Koch R. Schöllhorn H. Eickenbusch 《Zeitschrift für Physik B Condensed Matter》1987,69(1):1-9
The ac-Josephson effect could be demonstrated up to dc voltages of 20 mV on the I–V characteristic of adjustable YBa2Cu3O7/YBa2Cu3O7 point contacts at 4.2 K. A detailed analysis of the rf power dependence of the size of microwave-induced constant voltage steps is given for microwave frequencies of 70 and 90 GHz. The results prove that electron pairing is responsible for the superconductivity in YBa2Cu3O7. 相似文献
19.
Mizokawa T Kim C Shen ZX Ino A Yoshida T Fujimori A Goto M Eisaki H Uchida S Tagami M Yoshida K Rykov AI Siohara Y Tomimoto K Tajima S Yamada Y Horii S Yamada N Yamada Y Hirabayashi I 《Physical review letters》2000,85(22):4779-4782
We compare the angle-resolved photoemission spectra of the hole-doped Cu-O chains in PrBa2Cu3O7 (Pr123) and in PrBa2Cu4O8 (Pr124). While, in Pr123, a dispersive feature from the chain takes a band maximum at k(b) (momentum along the chain) approximately pi/4 and loses its spectral weight around the Fermi level, it reaches the Fermi level at k(b) approximately pi/4 in Pr124. Although the chains in Pr123 and Pr124 are approximately 1/4 filled, they show contrasting behaviors: While the chains in Pr123 have an instability to charge ordering, those in Pr124 avoid it and show an interesting spectral feature of a metallic coupled-chain system. 相似文献
20.