“International Workshop on Construction of Low-Carbon Society Using Superconducting and Cryogenics Technology” , March 7-9, 2016, Cosmo Sauare Hotel & Congress, Osaka Jpan

Development Of REBCO Coated Conductors Utilizing Artificial

Pinning Center Technology

Kaname MatsumotoKyushu Institute of Technology

JSPS-Kiban S & JST-ALCA

Kyushu Institute of Technology 1

Collaborators

2

Yutaka Yoshida (Nagoya Univ.)

Satoshi Awaji (Tohoku Univ.)

Yoshihiko Takano (NIMS)

supported by JST-ALCA

Issues in coated conductor R&D

3

Critical current control

Low cost production process

Mechanical properties

Thermal stability

Quench protection

Screening current

so on ….

Critical current, flux pinning issues

max

p pp

dU Uf

dx

p c p pF J B n f4

REBCO coated conductor

Artificial pinning centers (APCs)

5K. Matsumoto et al., 2004 5

Artificial pinning centers “APCs” -nanorodNanorods

BaZrO3, BaSnO3, Double perovskite, BaHfO3 ,etc

J. MacManus‐Driscoll et al., Nature Mat. 3, 439 (2004) 

BaZrO3 column

D. Feldmann et al., SUST 23, 095004 (2010) 

Ba2YNbO6 nanorods

Fpmax = 32.3 GN/m3 at 75 K, B//c

H. Tobita et al., SUST 25, 062002 (2012) J. Hanisch et al., SUST 19, 534 (2006) 

BaHfO3 nanorods

A. Tsuruta et al., SUST 27, 065001 (2014) 

Fpmax = 28.0 GN/m3 at 77.K, B//c

P. Mele et al., SUST 21, 032002 (2008) 

BaSnO3 nanorods

Fpmax = 28.3 GN/m3 at 77 K, B//c

C. Varanasi et al., APL 93, 092501 (2008) 

✓ Selection of material and

✓ Straightness of nanorods✓ Appropriate diameter of nanorods

✓ Sharp interface

✓ High density without Tc suppression

6

Nanoparticles

Artificial pinning centers -nanoparticles

Y211, Y2O3, BaZrO3, BaSnO3, etc

T. Haugan et al., Nature 430, 867 (2004)

Y211 particles

P. Mele et al., SUST 20, 616 (2007)

Y2O3 particles

Fpmax = 16 GN/m3 at 77 K, B//c

J. Gutierrez et al., Nature Mat. 6, 367 (2007)

BaZrO3 particles

Fpmax = 21 GN/m3 at 77 K, B//c

A. Llordes et al., Nature Mat. 11, 329 (2012)

BaZrO3 particles

Nanoscale strain

M. Miura et al., SUST 26, 035008 (2013)

BaZrO3BaSnO3BaNbO3pure

✓ Selection of material and

✓ Appropriate diameter of nanoparticles

✓ High density without Tc suppression

✓ Sharp interface

✓ Surrounding additional defects

7

0 1 2 3 4 5 6 7 8 90

5

10

15

20

25

30

F p [G

N/m

3 ]

Magnetic Field [T]

1.0 vol.% 4.2 vol.% 2.3 vol.% 4.4 vol.% 3.2 vol.% 3.7 vol.%

Fp-B (BHO doped SmBCO / LAO)

@ 77 KB//c

YBCO+BSO28 GN/m3 (3 T)

Fp-B with different amounts of BHO content

28.0

8

Surface morphologies of SmBCO+BMO/LAO

Pure BSO BHO(1 μm × 1 μm)

(2 μm × 2 μm)

pits existed along the step edges of the growth islands BSO&BHO pinned the growth of the SmBCO layer

9

PLD-Sm123+10%BHO/LaAlO3

Introduction of nanorods into REBCO wires

Awaji  et al., 2012 10

11Critical current density and resistivity properties

(Awaji, JSAP2014Autumn)

Jc(B)5.6vol%Jc(B)1.6vol%

ρ(B)1.6vol% ρ(B)5.6vol%

Jc and ρ have plateau. 11

12

Critical current and resistivity map

Jc(B, T)

ρ(B, T)

Jc(B, T)

ρ(B, T)

12

Irreversibility line

Fig. Irreversibility lines for each film in B//c.

15.5 T

10.8 T

9.8 T

Birr of BHO-doped SmBCO film was higher in all temperature.⇒higher Tc and strong flux pinning force in high magnetic fields

78 80 82 84 86 88 90 92 940

2

4

6

8

10

12

14

16

18

B//c

Irre

vers

ibili

ty fi

eld

[T]

Temperature [K]

pure SmBa2Cu3Oy BaZrO3-doped SmBa2Cu3Oy BaHfO3-doped SmBa2Cu3Oy BaSnO3-doped SmBa2Cu3Oy14.0 T

13

Microstructure in SmBCO+BMO film fabricated by Low Ts from TEM images

LAO

(a) Tsupper = 840 oC

Seed layer

Upper layer[001] SmBCO

(b)

LAO

Tsupper = 750 oC

Seed layer

Upper layer[001] SmBCO

High number densitySmall diameter

tilt for c-axis

Straight Low number density

Similar to a PLD sample[3]

[3] A. Tsuruta et al. : IEEE. Trans. Appl. Supercond. 23 (2013) 8001104 14

Fp-B at 77 K and lower temperatures

0 2 4 6 8 10 12 14 16 180

100

200

300

400

500

600

700

800

900

LTG @ 40 K

PLD @ 40 K

PLD @ 20 K

LTG @ 20 K

B//c

Flux

pin

ning

forc

e de

nsity

, Fp [G

N/m

3 ]

Magnetic field, B [T]0 2 4 6 8 10 12 14 16

0

5

10

15

20

25

30

35

40

@ 77 K, B//c

Flux

pin

ning

forc

e de

nsity

, Fp [G

N/m

3 ]

Magnetic field, B [T]

PLD (SmBCO + BHO)High Fp @ 77 K [3]

LTG

Fp-B at 77 K

Fp-B at lower temperatures

Film FpMAX at 77 K Fp

MAX at 40 K FpMAX at 20 K

LTG 5.6vol% 14.2 GN/m3 407 GN/m3 779 GN/m3

PLD high Fp sample 28.0 GN/m3 226 GN/m3 437GN/m3

Table Maximum Fp of the LTG and PLD high Fp films.Fig. Magnetic field dependence of Fp of the LTG and PLD high Fp films.

S. Miura, Y. Yoshida, Supercond.Sci.Technol.28 (2015) 11400615

Higher Fp of LTG-Sm123 + BHO at 4.2K

S. Miura, Y. Yoshida submitted

Higher Fp reached not only at 77K and but also at lower temperature using LTG SmBCO+BHO / LAO fabricated at optimum Ts and BMO volume.

Higher Fp at 10K and 4.2K using LTG SmBCO+BHO fabricated at optimum Ts and BMO volume.

Fp at lower temperature is 650 GN m-3, 1.1TN m-3 and 1.6TN m-3 at 20K, 10K and 4.2 K, respectively. 0 2 4 6 8 10 12 14 16 18

0

200

400

600

800

1000

1200

1400

1600

1800

@ 20 K

@ 4 K

@ 10 K

LTG-Sm123 + 3.0 vol.% BHO , Tsupper = 720℃

@ B//c

F p [GN

/m3 ]

Magnetic field, B [T]

@4.2K

Fp=4.0GN m-3 at 77 K

16

Flux pinning performances of REBCO wires

17

18Flux pinning force– High Temp. & Low Field –

Many rods

Single rod

18

19

When temp. decreases, the contribution of random pins is enhanced in comparison with that of correlated pin with 1/Bi.

Model calculation using the cooperation model of pins.

Comparison to the experimental data

19

Prediction of Jc by TDGL simulations

Current density J/Jd

Voltage

V/V

0

T=0, H/Hc2= 0.4, No pinning

H/Hc2=0.3

H/Hc2= 0

0.1

0.20.3

0.4

20

YBCO+BSO layer

Intermediate layer

Hastelloy layer

YBCO+2wt%BSO+0.691A%Y2O3 YBCO+4wt%BSO+0.691A%Y2O3

Hybrid APC approach YBCO‐IBAD

IBAD-YBCO coated conductors with hybrid APCs

21

Jc() of REBCO films with nanorods and hybrid APCs

nanorods hybrid APCs

22

23

Most successful wires : NbTi wires

P. J. LeeD. C. Larbalestier

http://fs.magnet.fsu.edu/~lee/image/nbti/index.htm

P. J. Lee et al, 2001

23

Summary

24

Artificial pinning center (APC) technology is veryuseful to control Jc of REBCO wires

Performances of REBCO films have beenimproved by introduction of APCs such asnororods and nonoparticles

Fpmax values of REBCO films and wires with APCshave reached 1,750 GN/m3 (1.75 TN/m3) at 4.2 K,which is two order of magnitude higher than thatof NbTi wire at 4.2 K (16.5 GN/m3)

More higher Fpmax is expected by introduction ofAPCs with 10-20 % volume fraction