The effect of adding Ba2TiSi2O8 to the pure or Mn-doped titanate was studied by means of high-temperature conductivity measurements and analytical electron microscopy. The diffusivity (tables 18 and 19) was deduced from the resistivity changes which occurred during changes in the O partial pressure. The results showed that the additive precipitated, during cooling, as a second crystalline phase. Only a small amount of amorphous phase remained in a few grain boundaries. The secondary crystalline phase incorporated excess Mn which was left over from the heterogeneous doping of the titanate.

J.Weiss, G.Rosenstein: Journal of Materials Science, 1988, 23[9], 3263-71

 

 

 

Table 18

Diffusion of O in BaTiO3 with Various Additions

 

Addition

Content (wt%)

Temperature (C)

Process

D (cm2/s)

-

-

810

out-diffusion

6.9 x 10-5

-

-

905

out-diffusion

1.5 x 10-4

-

-

905

in-diffusion

6.6 x 10-5

-

-

998

out-diffusion

2.0 x 10-4

-

-

998

in-diffusion

4.2 x 10-4

Si2Mn0.05O8.1

1

815

out-diffusion

6.6 x 10-5

Si2Mn0.05O8.1

1

908

out-diffusion

1.5 x 10-4

Si2Mn0.05O8.1

1

908

in-diffusion

5.1 x 10-6

Si2Mn0.05O8.1

1

995

out-diffusion

1.3 x 10-4

Si2Mn0.05O8.1

1

995

in-diffusion

1.7 x 10-4

Si2Mn0.05O8.1

8

815

out-diffusion

4.5 x 10-5

Si2Mn0.05O8.1

8

815

in-diffusion

1.4 x 10-5

Si2Mn0.05O8.1

8

907

out-diffusion

5.3 x 10-5

Si2Mn0.05O8.1

8

907

in-diffusion

1.0 x 10-5

Si2Mn0.05O8.1

8

995

out-diffusion

6.3 x 10-5

Si2Mn0.05O8.1

8

995

in-diffusion

4.0 x 10-5

 

 

 

Table 19

Diffusion of O in Ba103.75Ti100.6Mn2Ox with Various Additions

 

Addition

Content (wt%)

T (C)

Process

D (cm2/s)

-

-

1018

out-diffusion

2.5 x 10-4

-

-

1018

in-diffusion

1.5 x 10-4

Ba1.5Ca0.5TiSi2O8

1

1001

out-diffusion

8.3 x 10-5

Ba1.5Ca0.5TiSi2O8

1

1001

in-diffusion

4.7 x 10-5

Ba1.5Ca0.5TiSi2O8

2

1002

out-diffusion

6.2 x 10-5

Ba1.5Ca0.5TiSi2O8

2

1002

in-diffusion

5.3 x 10-5