High Temperature Superconducting Compounds.
Abstract
The properties of high temperature superconducting compounds, mostly in the form of thin films and thin film devices have been investigated. The main focus of the research was on the use of ozone-assisted molecular beam epitaxy in a shuttered growth mode to produce such films and structures. In addition to superconducting films, non-superconducting mixed-valence manganite perovskites, which exhibit so-called colossal magnetoresistance were grown. The manganites are unique in that their charge carriers are believed to be almost 100% spin polarized. These materials were combined with the curates to produce heterostructures in which the suppression of superconducting properties, such as the critical current and critical temperature, was brought about by the injection of spin polarized carriers from the manganite into the curate. This work may make possible new classes of devices based on this nonequilibrium spin injection phenomenon. The symmetry of the pairing state of high temperature superconductors was also investigate, with the objects of study being high-quality single crystals. The results of this work suggest that the pairing is not pure d-wave, but is a time-reversal violating state which is an admixture of s and d - wave symmetries in the form s + id.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 02, 1999
- Accession Number
- ADA362342
Entities
People
- Allen M. Goldman
Organizations
- University of Minnesota