Vf. Kraidenov et Es. Itskevich, THE THERMO-EMF OF THE SUPERCONDUCTING CER AMIC YBA2CU4O8 UNDER HYDROSTATIC-PRESSURE OF UP TO 10 KBAR, Fizika nizkih temperatur, 19(7), 1993, pp. 835-837
The authors investigated the temperature dependence of the thermo-emf
alpha of the ceramic YBa2Cu4O8 under hydrostatic pressure of up to 10
kbar in the temperature range 4.2-300 K. At all T and P the thermo-emf
was positive and had a minimum at T almost-equal-to 150 K. and the su
perconducting transition temperature was T(c) almost-equal-to 80 K. In
creasing pressure caused alpha to rapidly drop and T(c) to increase, s
o that d In alpha/dP = -4.10(-5) kbar-1 and dT(c)/dP = 0.48 K/kbar. A
similar strong dependence of alpha and T(c) on P was earlier observed
on YBa2Cu3Ox with deficiency of oxygen, x = 6.5-6.6.