摘要:

The critical thickness for coherent growth of CdTe on ZnTe by molecular beam epitaxy is assessed by reflection high‐energy electron diffraction, low‐temperature photoluminescence, and transmission electron microscopy. The value is found to be 5 monolayers for this high mismatch system (6%). As opposed to similar studies on III‐V and Si‐Ge systems, there is no evidence of island formation before relaxation by dislocations at the interface.

ISSN:0003-6951    

DOI:10.1063/1.102812

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Insituepitaxial growth of Bi2(Sr,Ca)3Cu2Oxfilms was performed by ion beam sputtering in atomic oxygen ambience at the substrate temperature of 640 °C. The films showed an epitaxial growth in which theaandbaxes were parallel to ⟨100⟩ MgO, and the superstructure according to the incommensurate modulation along thebaxis was also observed. The superconducting properties of the as‐grown films seemed to sensitively depend on the oxidation treatment during the cooling down process. The zero resistivity temperatureTc(R=0) of a 600‐A˚‐thick film cooled down in the same atomic oxygen density as the film growth ambience was 60 K, but it increased up to 80 K after a post‐deposition annealing at 500 °C for 1 h in air. In contrast, as‐grown films cooled down in insufficient oxidation ambience showed theTc(R=0) of 76 K without post‐deposition annealing. The control of the oxygen concentration is critical for the superconductivity of as‐grown films.

ISSN:0003-6951    

DOI:10.1063/1.103286

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A large enhancement of critical current density with the small rate of flux creep was realized by x‐ray irradiation before the oxygen annealing for Gd1Ba2Cu3O7−xsuperconducting thin films. The significantly increased magnetization showed both the temperature independence and the small magnetic relaxation. The activation energy estimated by the flux creep model increased from 0.1 to 0.25 eV with the x‐ray irradiation treatment.

ISSN:0003-6951    

DOI:10.1063/1.103287

出版商:AIP    

年代:1990

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.103339

出版商:AIP    

年代:1990

数据来源: AIP