Irmantas Barnackas, prof. L. PranevičiusLithuanian Energy Institute

2006 02 03

Destabilization of Mg-based hydrogen storage materials: experimental results

To synthesize destabilized MgHTo synthesize destabilized MgH22 hydride and to investigate the hydride and to investigate the

hydride propertieshydride properties

The main goal of the workThe main goal of the work

Experimental technique: Experimental technique:

• to produce nanocrystalline Mg, Mg-Ti thin film materials using magnetron sputtering;

• to hydrogenate Mg, Mg-Ti thin films in high hydrogen pressure and temperature (p,T);

• to study Mg, Mg-Ti thin films de-hydrogenation kinetics using GDOES techniques;

• to analyze Mg, Mg-Ti thin films properties of as-deposited, after hydrogenation and de-hydrogenation using XRD, SEM and GDOES methods.

Quartz substrate

Mg film

Ti layer

Quartz substrate

Ti layer

Mg film

Quartz substrate

Mg + Ti film

UUTiTi = 490 V, I = 490 V, ITi Ti = 0.5 A, t = 5 sec.= 0.5 A, t = 5 sec.

UUMgMg = 420 V, I = 420 V, IMg Mg = 1 A, t = 5 min.= 1 A, t = 5 min.

UUTiTi = 480 V, I = 480 V, ITi Ti = 0.5 A, t = 5 sec.= 0.5 A, t = 5 sec.

UUMgMg = 405 V, I = 405 V, IMg Mg = 1 A, t = 5 min.= 1 A, t = 5 min.

UMg = 410 V, IMg = 1 AUTi = 440 V, ITi = 0.5 A t = 5 min.

Parameters of as-deposited Mg and MgTi films :Parameters of as-deposited Mg and MgTi films :

Quartz substrate

Mg film UUMgMg = 420 V, I = 420 V, IMg Mg = 1 A, t = 5 min.= 1 A, t = 5 min.

Pressure (Ar) – 0.4 PaPressure (Ar) – 0.4 Pa U UBIASBIAS = -100 V, = -100 V,

I IBIASBIAS = 10-60 mA = 10-60 mA

Parameters of hydrogenation/dehydrogenation of Mg, MgTi thin films Parameters of hydrogenation/dehydrogenation of Mg, MgTi thin films in high hydrogen pressure and temperature (p,T)in high hydrogen pressure and temperature (p,T)

Parameters of hydrogenation: Pressure (H2) – 8-11 bar

Temperature – RT – 320 0CHydrogenation duration – 6 hour

Parameters of dehydrogenation: Temperature – RT – 450 0CDehydrogenation duration – 60 min.

As-deposited Mg film: - XRD and SEM analysis

XRD diffractogram of as-deposited Mg film on quartz substrate

SEM micrograph of as-deposited Mg film on quartz substrate

10 20 30 40 50 60 700

500

1000

1500

2000

2500

3000

DMg 1-1

h-Mg(103)h-Mg(102)h-Mg(101)

h-Mg(002)

P(Ar) = 0.4 PaU

pries = -100 V, I

pries = 10 mA

Uznesimo schema : UMg

= 420 V, IMg

= 1 A

t = 5 min.

M g d a n g a

K v a r c a s

Inte

nsi

ty, a

rb.u

.

Diffraction angle, 2 theta

Hydrogenation/dehydrogenation kinetics of Mg film: Hydrogenation/dehydrogenation kinetics of Mg film: - XRD and SEM analysis

SEM micrograph of Mg film: (a) after hydrogenation; (b) after dehydrogenation

10 20 30 40 50 60 700

500

1000

1500

2000

2500

3000

3500

4000

DMg 1-1 VHG

h-Mg(101)

t-MgH2(211)

t-MgH2(101)

h-Mg(102)h-Mg(101)

h-Mg(002)

h-Mg(103)

DMg 1-1

c-MgO(220)

c-MgO(200)

T = 450 0C, t = 6 hDehidrinimo parametrai:

Hidrinimo parametrai:

c-MgO(220)

c-MgO(200)

P(H2) = 8-11 bar

T = 320 0C, t = 6 h

DMg 1-1 VH

t-MgH2(110)

Inte

nsy

vum

as, s

ant.

v.

Difrakcijos kampas, 2 teta

XRD analysis of XRD analysis of Mg film after hydrogenation/dehydrogenation processes

b

a

DMG 1-1VH

0

5

10

15

20

25

30

35

40

45

0 500 1000 1500 2000 2500 3000 3500 4000

Time, s

Inte

ns

ity

, a

rb.u

.

0

100

200

300

400

500

600

Te

mp

era

ture

, C

Desosiation curveTemperature curve

78°C

33°C

168°C

298°C

438°C

Studies of deStudies of de--hydrhydrogenationogenation kinetics of Mg thin films kinetics of Mg thin films

As-deposited Mg-Ti film: - XRD and SEM analysis

10 20 30 40 50 60 700

500

1000

1500

2000

2500

3000

h-Mg(102)h-Mg(101)

h-Mg(002)h-Mg(103)

P(Ar) = 0.4 PaU

pries = -100 V, I

pries = 10 mA

UMg

= 420 V, IMg

= 1 A

t = 5 min.

UTi = 490 V, I

Ti = 0.5 A

t = 5 sek.Uznesimo schema :

Mg danga

T i d an g a

K v a rc a s

DMg 13-1

Ti etalonas

Mg etalonas

Inte

nsy

vum

as, s

ant.

v.

Difrakcijos kampas, 2 teta

XRD diffractogram of as-deposited MgTi film on quartz substrate

SEM micrograph of as-deposited MgTi

film on quartz substrate

Hydrogenation/dehydrogenation kinetics of Mg-Ti film: Hydrogenation/dehydrogenation kinetics of Mg-Ti film: - XRD and SEM analysis

10 20 30 40 50 60 700

500

1000

1500

2000

2500

3000

P(H2) = 8-11 bar

T = 320 0Ct = 6 h

c-MgO(220)c-MgO(200)

DMg 13-1 VH

h-Mg(102)h-Mg(101)

h-Mg(002)h-Mg(103)

DMg 13-1

Inte

nsy

vum

as, s

ant.

v.

Difrakcijos kampas, 2 teta

XRD analysis of XRD analysis of Mg-Ti film after hydrogenation process

SEM micrograph of MgTi film after hydrogenation

As-deposited Mg-Ti film: - XRD and SEM analysis

10 20 30 40 50 60 700

500

1000

1500

2000

2500

3000

h-Mg(002) h-Mg(103)

P(Ar) = 0.4 PaU

pries = -100 V, I

pries = 10 mA

UMg

= 405 V, IMg

= 1 A

t = 5 min.

UTi = 480 V, I

Ti = 0.5 A

t = 5 sek.

Uznesimo schema : Mg danga

T i d a n g a

K v a rc a s

DMg 18-2

Ti etalonas

Mg etalonas

Inte

nsyvu

mas, san

t.v.

Difrakcijos kampas, 2 teta

XRD diffractogram of as-deposited MgTi film on quartz substrate

SEM micrograph of as-deposited MgTi film on quartz substrate

10 20 30 40 50 60 700

500

1000

1500

2000

2500

3000

3500

4000

h-Mg(102)h-Mg(101)

h-Mg(002)h-Mg(103)

Mg danga

c-MgO(220)c-MgO(200)

T = 450 0C, t = 6 hDehidrinimo parametrai:

Hidrinimo parametrai:

DMg 18-2 VHG

c-MgO(220)c-MgO(200)

P(H2) = 8-11 bar

T = 320 0C, t = 6 h

DMg 18-2 VH

h-Mg(002) h-Mg(103)

DMg 18-2Inte

nsyv

um

as, san

t.v.

Difrakcijos kampas, 2 teta

Hydrogenation/dehydrogenation kinetics of Mg-Ti film: Hydrogenation/dehydrogenation kinetics of Mg-Ti film: - XRD and SEM analysis

a

b

XRD analysis of XRD analysis of MgTi film after hydrogenation/dehydrogenation processes

SEM micrograph of MgTi film: (a) after hydrogenation; (b) after

dehydrogenation

DMg 18-2VH

0

10

20

30

40

50

60

0 500 1000 1500 2000 2500 3000 3500 4000

Time, s

Inte

nsit

y, arb

. u

.

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

450.00

500.00

Te

mp

era

ture

, C

Disosiation curveTemperature curve

35.5°C

68°C

200°C 265°C

378°C

380°C

390°C

400°C

Studies of deStudies of de--hydrhydrogenationogenation kinetics of Mg-Ti thin films kinetics of Mg-Ti thin films

As-deposited Mg-Ti film: - XRD and SEM analysis

10 20 30 40 50 60 700

500

1000

1500

2000

2500

3000

?? Ti arba Mg

xTi

y faze

t = 5 min. Mg + Ti danga

Kvarco padėklas

P(Ar) = 0.4 PaU

pries = -100 V, I

pries = 40 mA

UMg

= 410 V, IMg

= 1 A

UTi = 440 V, I

Ti = 0.5 A

Uznesimo schema :

DMg 21-2

Ti etalonas

Mg etalonas

Inte

nsy

vum

as, s

ant.

v.

Difrakcijos kampas, 2 teta

XRD diffractogram of as-deposited MgTi film on quartz substrate

SEM micrograph of MgTi film after hydrogenation

Hydrogenation/dehydrogenation kinetics of Mg-Ti film: Hydrogenation/dehydrogenation kinetics of Mg-Ti film: - XRD and SEM analysis

10 20 30 40 50 60 700

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

h-Mg(101)

r-Ti2O

3(116)

h-Ti(002) c-MgO(220)c-MgO(200)

T = 450 0C, t = 1 hDehidrinimo parametrai:

Hidrinimo parametrai:

Gryna Mg danga

h-Mg(103)h-Mg(102)h-Mg(101)h-Mg(002)

DMg 21-2 VHG

DMg 21-2 VH

? Mg, Ti, MgH2, TiH

2, TiO...

c-MgO(220)c-MgO(200)

P(H2) = 8-11 bar

T = 320 0Ct = 6 h

? Ti arba MgxTi

y faze

DMg 21-2

Inte

nsy

vum

as, s

ant.

v.

Difrakcijos kampas, 2 teta

XRD analysis of XRD analysis of MgTi film after hydrogenation/dehydrogenation processes

a

b

SEM micrograph of MgTi film: (a) after hydrogenation; (b) after

dehydrogenation

DMg 21-2VH

0

1

2

3

4

5

6

7

8

0 500 1000 1500 2000 2500 3000 3500 4000

Time, s

Inte

nsi

ty, a

rb. u

.

0

50

100

150

200

250

300

350

400

450

500

Tem

per

atu

re, C

Disosiation curveTemperature curve

23°C

60°C

163°C

175°C

210°C

330°C

365°C

405°C

Studies of deStudies of de--hydrhydrogenationogenation kinetics of Mg-Ti thin films kinetics of Mg-Ti thin films

10 20 30 40 50 60 700

10000

20000

30000

40000

? (TiO2 arba Mg

xTi

y fazes)

h-Mg(101)

t = 5 min. Mg + Ti danga

Kvarco padėklas

P(Ar) = 0.4 PaBe priesitampio !!!

UMg

= 410 V, IMg

= 1 A

UTi = 500 V, I

Ti = 1 A

Uznesimo schema :

DMg 20-1

Inte

nsy

vum

as, s

ant.

v.

Difrakcijos kampas, 2 teta

XRD diffractogram of as-deposited MgTi film on quartz substrate

As-deposited Mg-Ti film: - XRD and SEM analysis

SEM micrograph of MgTi film after hydrogenation

Hydrogenation/dehydrogenation kinetics of Mg-Ti film: Hydrogenation/dehydrogenation kinetics of Mg-Ti film: - XRD and SEM analysis

10 20 30 40 50 60 700

10000

20000

30000

c-MgO(200)

? (MgxTi

y phase)

c-MgO(220)h-Ti(101)

T = 450 0C, t = 1 hDehidrinimo parametrai:

Hidrinimo parametrai:

DMg 20-1 VHG

P(H2) = 8-11 bar

T = 320 0C, t = 6 h

h-Mg(002)

h-MgH2(102)

DMg 20-1 VH

? MgxTi

y phase

h-Mg(101)

DMg 20-1

Inte

nsy

vum

as, s

ant.

v.

Difrakcijos kampas, 2 teta

XRD analysis of XRD analysis of MgTi film after hydrogenation/dehydrogenation processes

a

b

SEM micrograph of MgTi film: (a) after hydrogenation; (b) after dehydrogenation

Studies of deStudies of de--hydrhydrogenationogenation kinetics of Mg-Ti thin films kinetics of Mg-Ti thin filmsDMg 20-1 VH

0

10

20

30

40

50

60

70

0 500 1000 1500 2000 2500 3000 3500 4000

Time, s

Inte

nsi

ty, a

rb. u

.

0

50

100

150

200

250

300

350

400

450

500

Tem

per

atu

re, C

Disosiation curveTemperature curve

23°C

90°C

165°C

235°C

273°C

295°C

410°C

ConclusionsConclusions

1. 2 µm Mg and MgxTiy thin films were successfully deposited on the quartz substrates using magnetron sputtering.

2. After the hydrogenation of pure Mg thin films in hydrogen atmosphere, in high pressure and high temperature, MgH2 thin films were successfully formed.

3. The MgTi thin film deposited without bias voltage and hydrided in high pressure and high temperature (p,T) at 320 0C for 6 hour transforms to MgH2.