No.

Concentration of

cerium nitrate (M)

Concentration of

cobalt nitrate (M)

Aging temperature

(˚C)

A1

0.5

0.1

25

A2

0.5

0.3

25

A3

0.5

0.5

25

B1

0.5

0.1

0

B2

0.5

0.3

0

B3

0.5

0.5

0

C1

0.5

0.1

70

C2

0.5

0.3

70

C3

0.5

0.5

70