Structural, thermal and crystallization kinetics of ZnO-BaO-SiO 2-B2O3-Mn2O3 based glass sealants for solid oxide fuel cells

Abstract

Glass

compositions

in

the

system

40SiO2–30BaO–20ZnO–(x)Mn2O3–(10

x)B2O3glasses

have

been

synthesized

and

the

thermal,

structural and

crystallization

kinetic

properties

characterized.

The

lower

concentration

of

Mn2O3in

place

of

B2O3acts

as

a

network

former

and

suppressed the

tendency

of

phase

separation

in

glasses.

On

the

other

hand,

concentration

of

Mn2O3>

7.5

mol%

induce

phase

separation

in

the

glass

matrix. The

highest

activation

energy

for

crystallization

is

observed

in

the

composition

without

B2O3 (INM4)

(355

kJ/mol).

The

values

of

thermal expansion

coefficient

(TEC)

and

viscosity

of

this

glass

is

8

10 6K 1and

104.2dPa

s

(850

8C),

respectively.

After

long

heat

treatment

(800

8C

for 100

h),

thermodynamically

stable

hexacelsian

and

monoclinic

phases

are

formed.

These

phases

are

not

detrimental

to

SOFC

application.