Exploratory Synthesis Employing Unusual Synthesis Approaches.
Abstract
One of the areas we investigated for new superconductors is reduced oxides of niobium, One unusual synthesis approach to prepare these materials has been ion exchange reactions and another has been quenching reactions from very high temperatures. Many reduced niobium oxides in A-Nb-O ternary systems where A is an alkaline or alkaline earth metal have been reported. Some examples are LiNb02 (1), NaNbl0018 (2,) BaNb80i4 (3), Ba2Nbi5032 (4) and Ca0.75Nb306 (5). Some of strongly reduced niobates contain a Nb601206 cluster with metal-metal bonding as found in NaNbl00l8 (2), BaNb8014 (3), Ba2Nb15032 (4) and Rb4Al2Nb36070 (6). These cluster compounds seemed like particularly good candidates in view of the known superconducting Mo-S cluster compounds. Furthermore, it was reported that LiNb02 changed from a semiconductor to a superconductor with a Tc = 4.5 K by deintercalation of Li+ ions (7). This confirms the potential for superconductivity in reduced niobates. Recently, we discovered a new reduced rubidium niobium oxide, Rb1.51Nb10017, with a layered structure and having a Nb6012J06 cluster (8). This compound is not superconducting down to 4.2 K, but changing the electron concentration in the cluster seemed like a worthwhile goal. The Rb+ ions occupying the interlayer space appeared to be good candidates for deintercalation or ion exchange reactions.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 31, 1995
- Accession Number
- ADA302006
Entities
People
- Arthur W. Sleight
Organizations
- Oregon State University