The tracer diffusion of Ag in the c-direction of monocrystalline Bi2Cu2Sr2CaOx, and in dense polycrystalline specimens of the other materials, was investigated. The concentration profiles were measured by using secondary ion mass spectrometry and radiotracer plus serial-sectioning techniques, for the monocrystals and polycrystals, respectively. It was found that the diffusivities of Ag in the c-direction of Bi2Cu2Sr2CaOx at 500 and 600C, under 1atm of O were approximately 4 orders of magnitude lower than those which had been measured in polycrystalline samples. The bulk diffusivity of 110Ag in Cu3(Bi,Pb)2Ca2Sr2Ox (table 45) could be described by:

D(cm2/s) = 6.7 x 107exp[-334(kJ/mol)/RT]

at temperatures ranging from 600 to 817C, and was not very sensitive to O partial pressures of between 103 and 105Pa at 760C. The diffusivity of 110Ag in Bi2Sr2CuOx (table 46) could be described by:

D(cm2/s) = 1.55 x 102exp[-196(kJ/mol)/RT]

Tracer Diffusion of Ag in Bi2Sr2Can-1CunO2n+4. Y.Fang, J.L.Routbort: Journal of Applied Physics, 1994, 75[1], 210-5

Table 45

Bulk Diffusivity of 110Ag in Cu3(Bi,Pb)2Ca2Sr2Ox