THERMOPOWER OF CERAMIC HGBA2CA2CU3O8+X AN D HGBA2CA3CU4O10+X SUPERCONDUCTORS UNDER PRESSURE

The temperature dependence of thermopower alpha of a sample, contained 75% HgBa2Ca2Cu3O8+x (Hg-1223 phase) and 10% HgBa2Ca3Cu4O10+x (Hg-1234 phase), was studied in a 95-300 K temperature range under hydrostatic pressure up to 10 kbar. Two superconductive transitions were observed at 132 and 118 K, which were thought to be associated with Hg-1223 an d Hg-1234 phases, respectively. Pressure increases T-c of both phases with a rate of 0.2 K/kbar. At T = 200 K, d ln alpha/dP similar or equa l to 3,8 . 10(-3) kbar(-1).