A hot isostatic press (HIP) techniques has been used successfully to react and consolidate in one step the Hg based high-temperature superconductors (HTS's). Hot isostatic pressing (HIPping) overcomes some of the problems encountered in the quartz encapsulation technique typically used to make Hg based HTS samples, such as containing the high vapor pressures of Hg and avoiding explosions. The HIPping conditions for processing (i.e., range of temperature and pressure) are significantly different from those used in the quartz-encapsulation method. These differences seem to relax the stringent conditions on precursor processing required in other processing methods. Hg based HTS samples were successfully made from both nitrate and carbonate precursors, as well as from commercially available precursors. X-ray diffraction experiments indicated that the best materials were made with nitrate precursors and were composed of 1223 phase (66%), 1212 phase (33%) and a small amount of BaCuO2 (1%). We have HIPped powders and contained them in selected high-purity metal foils. We find that Au is a good containment material for processing as it reacts very little with the Hg compounds being formed. Ag, on the other hand, reacts extensively. Samples with densities as high as 97% of theoretical density were formed. This technique has been used to successfully fabricate component that may lead directly to devices.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering