The diffusion of O in undoped and Ag-doped single crystals was investigated by performing isothermal resistivity measurements at temperatures ranging from 550 to 750C. It was found that the diffusion coefficients for Ag-doped crystals were an order of magnitude lower than those for undoped ones (table 62). Furthermore, the activation energy for O diffusion was found to be considerably higher for Ag-doped crystals. Further analysis of the data indicated that doping with Ag stabilized the phase at higher O contents.

D.K.Aswal, S.K.Gupta, P.K.Mishra, V.C.Sahni: Superconductor Science and Technology, 1998, 11[7], 631-6

 

 

 

Table 62

Diffusivity of O in Cu3Ba2YO7

 

Sample

Experiment

Temperature (C)

D (cm2/s)

undoped

in-diffusion

550

2.77 x 10-6

undoped

in-diffusion

600

5.20 x 10-6

undoped

in-diffusion

650

9.24 x 10-6

undoped

out-diffusion

550

1.66 x 10-6

undoped

out-diffusion

600

2.77 x 10-6

undoped

out-diffusion

650

4.16 x 10-6

Ag-doped

in-diffusion

650

2.89 x 10-7

Ag-doped

in-diffusion

700

8.03 x 10-7

Ag-doped

in-diffusion

750

3.07 x 10-6

Ag-doped

out-diffusion

650

1.01 x 10-7

Ag-doped

out-diffusion

700

5.04 x 10-7

Ag-doped

out-diffusion

750

1.96 x 10-6