STRUCTURE AND SUPERCONDUCTING PARAMETERS OF POWDER COMPOSITES YBACUO-AG, PREPARED BY STATIC (COLD AND HOT) AND SHOCK PRESSINGS

To investigate effect of a technological scheme on the structure and s uperconducting parameters of powder composites YBaCuO-Ag, three modes of preparation of the powder mixtures were used: static (cold and hot) and shock pressings. Silver content C ranged from 0 to 50 vol.%. Orth orombicity degree b/a of the YBaCuO seramics proved to be practically independent of C up to C = 30 vol.% for static pressings, and it decre ased appreciably even at small C values for the shock-pressed samples. Critical temperature T-c and transport critical current density j(c) show similar behavior with a maximum at C approximate to 10 vol.% for static and hot pressings. Shock pressing results in significant deteri oration of these parameters.