ISSN:
1573-7357
Keywords:
61.16.Ch
;
74.50.+r
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Very pure YBa2Cu3O7−δ (YBCO) single crystals grown in BaZrO3 crucibles are studied in the as-grown and the oxidized state by scanning force (SFM), friction force (FFM) and scanning tunneling microscopies (STM). The images show clean terraces with step-heights of one unit cell along YBCO(001), i.e. 1.2 nm. Only close to step edges is material contrast observed by FFM indicating traces af flux. Some crystal surfaces exhibit over-layer features, such as star-like, ribbon-like and checkerboard-like structures, which exhibit friction contrast implying the presence of different materials on the surface. Tunneling spectroscopy at 4.7 K in high vacuum reveals a superconducting energy gap of 2Δ ≈ 26 me V.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00753891
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