Accession Number : ADA258281


Title :   Processing and Fabrication of High Temperature Oxide Superconductors


Descriptive Note : Final rept. 1 Sep 1988-30 Oct 1992


Corporate Author : SRI INTERNATIONAL MENLO PARK CA


Personal Author(s) : Johnson, Sylvia M ; Gusman, Michael I


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a258281.pdf


Report Date : 30 Nov 1992


Pagination or Media Count : 120


Abstract : Synthesis of YBa2Cu3O7-a superconductor powders by freeze-drying was developed. The freeze-drying process consists of forming a solution of Y and Cu nitrates and Ba acetate, freezing, sublimating the water and calcination. The effect of processing variables on the powder characteristics, including surface area, size, stoichiometry, agglomeration, were investigated. Stoichiometry control requires control of the chemistry of the system, and careful analysis of starting solutions is required to prepare powders of the desired composition. Powders were sintered into pellets and the superconducting behavior was evaluated. Stanford University served as a subcontractor and was responsible for most of the critical transition temperature and critical current measurements.


Descriptors :   *HIGH TEMPERATURE , *SUPERCONDUCTORS , *OXIDES , CONTROL , MEASUREMENT , TEMPERATURE , FABRICATION , VARIABLES , CHEMISTRY , FREEZING , SINTERING , YTTRIUM , DRYING , ACETATES , STOICHIOMETRY , BARIUM , TRANSITIONS , PELLETS , COPPER , NITRATES , TRANSITION TEMPERATURE , SURFACES , FREEZE DRYING , SYNTHESIS , WATER , POWDERS , PROCESSING


Subject Categories : Physical Chemistry
      Fabrication Metallurgy
      Electricity and Magnetism


Distribution Statement : APPROVED FOR PUBLIC RELEASE