| 505 / | HD | SUPERCONDUCTOR TECHNOLOGY: APPARATUS, MATERIAL, PROCESS | 
| 300 | DF | PROCESSES OF PRODUCING OR TREATING HIGH TEMPERATURE (Tc GREATER THAN 30 K) SUPERCONDUCTOR MATERIAL OR SUPERCONDUCTOR CONTAINING PRODUCTS OR PRECURSORS THEREOF {24} | 
| 500 | DF | .~ Heating, annealing, or sintering {1} | 
| 501 |  | .~.~ Bismuth (Bi) or thallium (Tl) containing |