magnetocaloricpropertiesof reactivelysinteredla(fe,co,si) 13 science and technology...delft days on...

Magnetocaloric properties of

reactively sintered La(Fe,Co,Si)13

M. Katter, V. Zellmann, G.W. Reppel, K. Uestuener

Vacuumschmelze GmbH & Co. KG

Delft Days on Magnetocalorics

Delft Days on Magnetocalorics 2008, M. Katter, La-Fe-Co-Si sintered page 2

overview magnetic materials

Pure Fe,

FeCo

C-Steels

Fe

Powder cores

Ni-Fe

Hard ferrites

Cu Ni Fe

AlNiCo

AmorphousCo-based

Nanocrystalline

FeNi (medium)

FeNi 80%(Permalloys)

FeSiAl

Cr-, Co- Steels

CoFeNiFeCoCrFeCoVFeMnNiTi

FeCoVCr

NdFeBRE-Co

MnAlC

Pt Co

Fe Cr Co

2.5

2.0

1.5

1.0

0.5

0

Sat

urat

ion

mag

netiz

atio

nJ

s/ T

soft magnetic hard magneticsemi hardmagnetic

Soft ferrites

Coercivity Hc /(A/cm)

2.5

2.0

1.5

1.0

0.5

00.1 1 10 100 103 1040.010.001

Rapid Solidification Rolling Process Powder Route

FeNiAlTi

3%FeSi

Rem

anec

eB

r/ T

NdFeBbonded

SMCPure Fe,

FeCo

C-SteelsC-Steels

Fe

Powder cores

Ni-Fe

Hard ferrites

Cu Ni Fe

AlNiCo

AmorphousCo-based

Nanocrystalline

FeNi (medium)

FeNi 80%(Permalloys)

FeSiAl

Cr-, Co- Steels

CoFeNiFeCoCrFeCoVFeMnNiTi

FeCoVCr

NdFeBRE-Co

MnAlC

Pt CoPt Co

Fe Cr Co

2.5

2.0

1.5

1.0

0.5

0

Sat

urat

ion

mag

netiz

atio

nJ

s/ T

soft magnetic hard magneticsemi hardmagnetic

Soft ferrites

Coercivity Hc /(A/cm) Coercivity Hc /(A/cm)

2.5

2.0

1.5

1.0

0.5

00.1 1 10 100 103 1040.010.001 0.1 1 10 100 103 1040.010.001

Rapid Solidification Rolling Process Powder Route

FeNiAlTi

3%FeSi

Rem

anec

eB

r/ T

NdFeBbonded

SMC


new magnetocaloric materials

K. Gscneidner (2007)

accessable withNd-Fe-B magnets


magnetocaloric materials

target operating range

most promising at the moment: La-Fe-Si

Spe

cific

etr

opy

dens

ity (

∆S/l/

∆H)

poisonous

expensive, limited temperature range

poisonous

small effectGdLaMnO3

MnFePAs

MnAsLaFeSi (…)

GdSiGe

Cooltech Applications (2008)


- casting- anneal, e.g. 1080°C/140 h- optionally load with hydrogen

⇒ long annealing times, ⇒ with hydrogen only powder

- melt spinning- short anneal, e.g. 1000°C/2 h

⇒ only flakes or powder, no shaped parts for heat exchangers

conventional preparation of La(Fe,Si)13

-30

-25

-20

-15

-10

-5

0

180 210 240 270 300 330 360

T (K)

∆∆ ∆∆S

m (

J/k

g K

)

La(Fe0.88Si0.12)13Hy

y = 0.0 0.5 1.0 1.5

S. Fujieda et al. 2005F.X. Hu et al. 2005 (with Co)

O. Gutfleisch et al. 2005S. Hirosawa et al. 2006


Designs for active magnetic regenerators

J.A. Barclay and S. Sarangi 1984 in A.M. Tishin and Y.I. Spichkin 2003

large pressure dropsin powder beds?


Powder Metallurgical (PM) Processing of La-Fe-Si

P

Vacuum InductionAlloying and Casting

Crushing

Milling

Blending

Pressing:CIP - die

isostaticpressing

die-pressing

elemental powders


Powder Metallurgical (PM) Processing of La-Fe-Si

P

Pressing:CIP - die

die-pressing

Isostaticpressing

Reactive Sintering

Machining and Surface Finishing


La(Fe0.915Si0.085)13

powder blend of Fe, Si and LaHx(no melting at all)

milled to F.S.S.S. < 5 µm

isostaticallypressed

sinteredat 1120°C/4h

density = 6.6 g/cm3 sample: 4,2 x 2 x 1,2 mm

0.00

0.20

0.40

0.60

0.80

1.00

1.20

-100 -95 -90 -85 -80 -75

temperature T (°C)

pola

rizat

ion

J (T

)

17.0

15.3

13.6

11.9

10.2

8.5

6.8

5.1

3.4

1.7

Kühlrate: - 14 K/min

H (kOe)


La(Fe0.893Si0.107)13, sintered

-30

-25

-20

-15

-10

-5

0

180 210 240 270 300 330 360

T (K)

∆∆ ∆∆S

m (

J/k

g K

)


y = 0.0 0.5 1.0 1.5

dHT

HTMS

HP

H

T,

0

),(∫

∂∂=∆

S. Fujieda et al. 2005, 0 - 2 bzw. 0 - 5 T

external magnetic field strength H (kOe)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

180 185 190 195 200 205 210

temperature T (K)

pola

rizat

ion

J (T

)

2,0

16

10

5

2

H (kOe)

0

5

10

15

20

25

180 185 190 195 200 205 210

temperature T (K)

- ∆∆ ∆∆S

mag

n (

J/kg

K) 16

12

8

4

H max (kOe)


0

1

2

3

4

5

180 190 200 210

temperature T (K)

∆∆ ∆∆T

adia

batic

(K

)

2,0

1423

1393

1373

1333

T s (K)

La(Fe0.915Si0.085)13, sintered

0

2

4

6

8

10

12

14

180 210 240 270 300 330 360

∆∆ ∆∆T

ad (

K)

T (K)


y = 0.0 0.5 1.0 1.5

-95-93-91-89-87-85-83-81-79-77-75

1800 1900 2000 2100 2200Zeit (s)

Pro

bent

empe

ratu

r (°C

)

T ProbeT-Regel

adiabatic temperature change

S. Fujieda et al. 2005, 0 - 2 bzw. 0 - 5 T

tem

pera

ture

T (

°C)

time t (s)

∆H = 1,7 T


thermal hysteresis

0.0

0.2

0.4

0.6

0.8

1.0

1.2

180 190 200 210

temperature T (K)

pola

rizat

ion

J (

T)

2 kOe

5 kOe

10 kOe

16 kOe

La(Fe 0.893Si0.107)13

0.0

0.2

0.4

0.6

0.8

1.0

1.2

190 200 210 220

temperature T (K)

pola

rizat

ion

J (

T)

2 kOe

5 kOe

10 kOe

16 kOe

La(Fe 0.881Si0.119)13

temperaturechange rate: 8 K/min

hysteresis decreaseswith increasingSi contentand field strength


field hysteresis

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 5000 10000 15000

magnetic field strength H (Oe)po

lariz

atio

n J

(T

)

195.5 K197.8 K200.0 K202.0 K204.4 K

La(Fe 0.881Si0.119)13

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 5000 10000 15000

magnetic field strength H (Oe)

pola

rizat

ion

J (

T)

188.7 K190.7 K192.9 K195,1 K197.0 K

La(Fe 0.893Si0.107)13

temperature decreasing at –8 K/min temperature increasing at +8 K/min temperature hysteresis

field hysteresis

-∆Smagn Tpeak ∆TWHH -∆Smagn Tpeak ∆TWHH ∆Tpeak ∆H composition

(J/kgK) (K) (K) (J/kgK) (K) (K) (K) (kOe)

La(Fe0.893Si0.107)13 21.9 192.7 6.6 22.0 195.2 6.6 2.5 2.2

La(Fe0.887Si0.113)13 18.7 196.5 7.0 18.9 198.9 7.0 2.4 1.6

La(Fe0.881Si0.119)13 16.9 202.2 6.7 16.2 202.9 7.2 0.7 0.9

field sweep rate: 4.3 kOe/min


La(Fe0.862Co0.05Si0.085)13sintered

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 5000 10000 15000

magnetic field strength H (Oe)

pola

rizat

ion

J (

T)

250.1 K253.2 K256.7 K260.3 K263.4 K

La(Fe 0.862Co0.05Si0.085)13

0,0

2,0

4,0

6,0

8,0

10,0

230 240 250 260 270 280

temperature T (K)

- ∆∆ ∆∆S

m (

J/kg

K)

4,0

8,0

12,0

16,0

Hmax (kOe)

allmost no hysteresis at all

ρ = 7.24 g/cm3

-∆Sm @16 kOe= 67 kJ/m3KTpeak = -19 °C

∆TWHH = 14 K


0,00

2,00

4,00

6,00

8,00

10,00

-30,0 -20,0 -10,0 0,0 10,0 20,0 30,0 40,0 50,0 60,0 70,0 80,0

T (°C)

- ∆∆ ∆∆S

m (J

/kgK

)

x = 0.050

x = 0.058

x = 0.065

x = 0.075

x = 0.087

x = 0.099

x = 0.112

Gd

sintered La(Fe0.915CoxSi0.085)13

several kgblocks 23x19x12 mmproduced onlabscale for prototyping

∆H = 16 kOe


thermal expansion of sintered La-Fe-Co-Si

-0,50

-0,45

-0,40

-0,35

-0,30

-0,25

-0,20

-0,15

-0,10

-0,05

0,00

-100 -50 0 50 100 150 200

temperature T (°C)

ther

mal

exp

ansi

on

∆∆ ∆∆l/l

(%)

difficult to machine

La(Fe0,865Co0,05Si0,085)13

La(Fe0,803Co0,112Si0,085)13


performance in a magnetic refrigeration prototype at

Risø National Laboratory for Sustainable Energy

25% ethylene glycol / water solution K.K. NielsenJ.B. JensenK. EngelbrechtCh. Bahl

2008


Adiabatic temperature change measured at Risø

∆H = 1.1 T

Cast bulk samples

F.X. Hu 2005

magnetizationmagnetization

demagnetizationdemagnetization

La(Fe0,85Co0,065Si0,085)13

La(Fe0,84Co0,075Si0,085)13

La(Fe0,855Co0,06Si0,085)13

K.K. NielsenJ.B. JensenK. EngelbrechtCh. Bahl

2008


Hydrogenation of sintered La-Fe-Co-Si

0

1

2

3

4

5

6

7

8

9

10

-50 0 50 100 150temperature T (°C)

ent

ropy

ch

ange

- ∆S

m (J

/kgK

)

La(Fe0,865Co0,05Si0,085)13H1,9

La(Fe0,806Co0,123Si0,071)13

∆H = 16 kOe

La(Fe0,865Co0,05Si0,085)13


Conclusion

- La(Fe,Si)13 sucessfully prepared by powder metallurgy

- bulk material available after reactive sintering for a few hours

- hysteresis decreases with increasing Si and Co content

- Curie temperature controllable by Co or H substitution

- entropy change similar or better compared to Gd

- several kg with various Curie temperatures produced

- process upscalable on an industrial basis

- temperature span comparable to Gd

0,00

2,00

4,00

6,00

8,00

10,00

-30,0 -20,0 -10,0 0,0 10,0 20,0 30,0 40,0 50,0 60,0 70,0 80,0

T (°C)

- ∆∆ ∆∆S

m (J

/kgK

)

x = 0.050

x = 0.058

x = 0.065

x = 0.075

x = 0.087

x = 0.099

x = 0.112

Gd

magnetocaloricpropertiesof reactivelysinteredla(fe,co,si) 13 science and technology...delft days on...

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