D.C. transport critical current measurements on high temperature superconductors in pulsed fields up to 50 T

1996 ◽  
Vol 32 (4) ◽  
pp. 2803-2805 ◽  
Author(s):  
D.T. Ryan ◽  
C.R.J. Hole ◽  
M. van der Burgt ◽  
H. Jones ◽  
C.M. Davies ◽  
...  
Keyword(s):  
High Temperature ◽  
Critical Current ◽  
High Temperature Superconductors ◽  
Pulsed Fields

Crystal Growth of High Temperature Superconductors

MRS Bulletin ◽  
1988 ◽  
Vol 13 (10) ◽  
pp. 56-61 ◽  
Author(s):  
H.J. Scheel ◽  
F. Licci
Keyword(s):  
High Temperature ◽  
Critical Current Density ◽  
Single Crystals ◽  
Critical Current ◽  
Current Density ◽  
Large Scale ◽  
High Temperature Superconductivity ◽  
High Temperature Superconductors ◽  
Superconducting Transition ◽  
Theoretical Understanding

The discovery of high temperature superconductivity (HTSC) in oxide compounds has confronted materials scientists with many challenging problems. These include the preparation of ceramic samples with critical current density of about 106 A/cm2 at 77 K and sufficient mechanical strength for large-scale electrotechnical and magnetic applications and the preparation of epitaxial thin films of high structural perfection for electronic devices.The main interest in the growth of single crystals is for the study of physical phenomena, which will help achieve a theoretical understanding of HTSC. Theorists still do not agree on the fundamental mechanisms of HTSC, and there is a need for good data on relatively defect-free materials in order to test the many models. In addition, the study of the role of defects like twins, grain boundaries, and dislocations in single crystals is important for understanding such parameters as the critical current density. The study of HTSC with single crystals is also expected to be helpful for finding optimum materials for the various applications and hopefully achieving higher values of the superconducting transition temperature Tc than the current maximum of about 125 K. It seems unlikely at present that single crystals will be used in commercial devices, but this possibility cannot be ruled out as crystal size and quality improve.

Interfaces in high-temperature superconductors

1992 ◽  
Vol 50 (1) ◽  
pp. 234-235
Author(s):  
K.L. Merkle ◽  
Y. Gao
Keyword(s):  
High Temperature ◽  
Critical Current ◽  
Weak Link ◽  
High Temperature Superconductors ◽  
Atomic Scale ◽  
Bulk Materials ◽  
Practical Applications ◽  
Metallic Contacts ◽  
Zero Resistance ◽  
Interfacial Characteristics

After the discovery of high-temperature superconductors (HTS) five years ago, it soon became apparent that their interfacial characteristics would play an extremely important role in any foreseeable applications of these materials. In recent commercial devices, the weak-link characteristics of grain boundaries (GBs) have in fact been exploited to manufacture Josephson junction SQUIDS. On the other hand, the low critical current density of HTS is a considerable limitation for practical applications of the zero-resistance property, particularly in bulk materials. The weak-link behavior of GBs is largely responsible for this, but other types of interfaces such as those formed by metallic contacts or the interfaces between the substrate and a HTS thin film are also critical to the application of these materials. We shall review here some of the important interface issues that have been addressed by TEM techniques, but shall focus largely on the connection between the critical current (Jc) that can be transported across a grain boundary and its atomic-scale structure and composition.

Sign in / Sign up

Export Citation Format

Share Document