recent advances in rebco coated conductors via …sang...electronic materials & devices...

Electronic Materials & Devices LaboratorySeoul National UniversityDepartment of Material Science & Engineering

Recent Advances in REBCO Coated Conductors

via the RCE-DR process

Sang-Im Yoo

Department of Materials Science & Engineering & Research Institute

of Advanced materials (RIAM), Seoul National University,

Seoul 151-744, Korea

ALCA-JST International Workshop Mar. 7-9, 2016 @ Osaka, Japan

Seoul National UniversityDepartment of Material Science & EngineeringElectronic Materials & Devices Laboratory

CollaboratorsGraduate Students in SNU (Seoul National University)

Dr. Jung-Woo Lee

(postdoc @ Univ. of Wisconsin)

Dr. Soon-Mi Choi

(Samsung Display Co.)

Mr. Tae-Hyun Seok

(SK Hynix)

Mr. Won-jae Oh

Dr. Hunju Lee

Researchers in SuNAM (Superconductor, Nano & Advanced Materials) Co.

Dr. Jae-Hun LeeDr. Seung-Hyun Moon

(CEO)

Researchers in KERI (Korea Electrotechnology Research Institute)

Dr. Hong-Soo Ha Dr. Sang-Soo Oh

New Graduate Students:Mr. In-Sung ParkMr. Jae-Eun KimMr. Duho Lee

Electronic Materials & Devices Laboratory Seoul National UniversityDepartment of Materials Science & Engineering

A New Coated Conductor Project in Korea

Funded by Ministry of Trade, Industry & Energy (MOTIE), Korea

through Inst. of Energy Tech. Evaluation and Planning (KETEP)

Critical current; IC > 1,000 A/cm @77 K, s.f.

(length > 1 km, uniformity > 96%)

In-field performance; IC > 1,000 A/cm @20 K, 10 T

Stacked conductor; IC > 1,800 A/cm @77 K, s.f.

IC measurement tech.; 0-10 T, > 1,800 A/cm, 20~77 K

DC reactor demo; 400 mH, 1,500 A

US$13M; $9M from Gov’t, $4M from SuNAM

(June 2013 ~ May 2017, 4 years)

Target

Budget


Outline

I. Introduction

SuNAM : Superconductor, Nano & Advanced Materials (瑞藍)

RCE-DR (Reactive Co-Evaporation Deposition & Reaction)

II. Recent Advances in REBCO CC

Optimization of conversion processing from an amorphous precursor to

REBCO film on the basis of phase stability diagrams in low PO2

Pinning improvement in GdBCO CCs by the RCE-DR process

III. Summary


Production Facilities of SuNAM Co.

Site area : 5,500 m2,

Building area : 1,750 m2,

Gross floor area : 3,050 m2.

Class < 10,000 clean

room area : 1,000 m2 .

Production capacity ~ 60 km/month(4 mm width) considering the yield(~ 70 %)

Introduction


Hastelloy C276 (Ni-alloy tape)

or

SUS-tape

Seed layer (Y2O

3)

~ 7 nm

IBAD-MgO layer ~ 10 nm

Homoepi-MgO layer ~ 20 nm

Diffusion barrier (Al2O3)

~ 40 nm

Hastelloy

or SUS

Al2O3

Y2O3

IBAD-MgO

Epi-MgO

LaMnO3

REBCO

Ag

Buffer layer ~20 nm

Superconducting layer (1 ~ 3 μm)

Protecting layer (1.5 mm)

IBAD(Sputter & E-beam)

Sputter

RCE-DR

DC sputter

Electro-polishing

( + Cu electroplating (+ lamination))

SuNAM HTS 2G Wire ArchitectureIntroduction


<Schematic of the RCE-DR process>

High rate deposition at low temperature & low oxygen pressure to a target thickness

(> 1 μm) at once in the deposition zone (6 ~ 10 nm/s)

Fast conversion by RCE-DR from an amorphous phase to superconductor at high

temperature and relatively higher oxygen pressure in the reaction zone

Simple, low system cost, easy to scale up (high deposition rate & large deposition area)

MOCVD (Superpower) : ~ 180 m/h 1)

PLD (Fujikura) : 20 m/h 2)

MOD (AMSC) : ~ 100 m/h 3)

RCE-DR (SuNAM) > 360 m/h 4)

1) 2008 DOE Superconductivity Peer Review, Superpower, Inc.

2) 2009 “RE123 Coated Conductors”, Fujikura Annual reports

3) 2009 DOE Superconductivity Peer Review, AMSC Co.

4) 2010 ISS S.H. Moon (SuNAM) invited talk,

2011 MRS spring meeting S.I. Yoo (SNU) invited talk

<Throughput of each processing

method – 4mm width equivalent >

RCE-DR : Reactive Co-Evaporation Deposition & Reaction

Introduction

RCE DR : ~ 100 nm/sec or faster (SuNAM)

PLD, MOCVD ~ 10 nm/sec, MOD ~ 1 nm/sec


IntroductionRecent report from SuNAM

J.H. Lee et al., Supercond. Sci. Technol. 27 (2014) 044018


SuNAM’s CC on STS 310S by standard daily production

Introduction

0 200 400 600 800 10000

100

200

300

400

500

600

700

800

900

Length (m)

I C (

A/1

2m

m)

Jc(77 K, 0T) > 4 MA/cm2

Min Ic (A/cm-width) x L (m) > 0.5 Million A-m

Production speed of 120 m/hr (12 mm width) with 1.4 mm thick film.

Introduction

[ Specification Table ]

Model AN CN LB/LS K

DescriptionSilver(+Cu…)Dry coating

CopperWet Coating

Brass/ Stainless steelLamination

Polyimide tape(+)Insulation

Substrate Hastelloy or Non-magnetic Stainless Steel

Width[ mm ]

Commercial : 4 mm, 12 mm.Special Order : 2 ~ 10 mm multi width is available

Thickness[ mm ]

HAS : 0.06~0.07SS* : 0.11~0.12

HAS : 0.09~0.11SS* : 0.14~0.16

HAS : 0.18~0.22SS* : 0.23~0.27

+ 0.1

FinalProcess

SilverSputter

CopperPlating

Brass or SS*Lamination

Wrapping

PieceLength

Above 100 m , 200 m , 300 m + without Splice

Min. Ic@ 77 k S.F.

(100 ) / 150 / 200 A + @ 4 mm (300 / 400) / 500 / 600 / 700 A + @ 12 mm

SuNAM’s 2G HTS Wire

(From Dr. Moon, CEO of SuNAM)

0 100 200 300 400 500 600 700 800 900 1000 11000

100

200

300

400

500

600

700

800

900

1000

Ic (

A/c

m-w

) @

77 K

Length (m)

●

10kAm

100kAm

200kAm

300kAm

Ic x L :

400kAm

500kAm

600kAm

700kAm

●

Development of HTS 2G Wire

(2009.8)

1065mx282A

(2008.10)

500mx300A

(2006.7)

100mx253A

(2010.10)

540mx466A

(2011.2)

816mx572A

(2014.03)

978mx579A

(2013.12)

860mx600A

2017 Goal

(2014.02)

270mx370A

(2016 Target)

500mx400A

(2014.11)

997mx601A

Introduction

http://terms.naver.com/entry.nhn?docId=1002827&cid=768&categoryId=1848

http://terms.naver.com/entry.nhn?docId=1002827&cid=768&categoryId=1848


Optimization of conversion processing from an amorphous

precursor to REBCO film on the basis of phase stability

diagrams in low PO2


II. Recent Advances in REBCO CC via RCE-DR


Objectives

To achieve higher performance GdBCO CC through the optimization of

RCE-DR processing

Development of a new pinning site applicable to the RCE-DR process

Motivation

A routine RCE-DR process of SuNAM should be improved for producing

higher performance GdBCO CCs and also developed for other REBCO CCs.

0.5 um1 0 0 n m

S.M. Choi et al., IEEE Trans. on Appl. Supercond. 23 (2013) 8001004

Motivation & Objectives


Stability phase diagram of GdBCO

log PO2(Torr) = 10.85 – 13,880/T(K)

[20PO2100mTorr]

log PO2(Torr) = 9.263 – 12,150/T(K)

[1PO210mTorr]

J.W. Lee et al., J Alloy Compd., 602 (2014) 78-86


500 nm

Gd

Ba

Cu

O

Cu

Cu

Cu

CuGd

Ba

Cu

O

O

CuCu

Gd

BaO

O

Gd2O3

GdBCO

Cu-O

• Very low PO2 zone (~ 10-5 Torr): Amorphous Film

• Lower PO2 zone (~30 mTorr): Gd2O3 + Liquid (< 5 sec)

• Higher PO2 zone (~100 mTorr): GdBCO Film (< 1min)

GdBCO growth mechanism: a seeded melt-textured growth!!!

Growth mechanism of the GdBCO film by RCE-DR


Production rate ≥ 360 m(4 mm width) / h

Control of conversion processing conditions

Processing routes for GdBCO CCs

880ºC 860ºC 840ºC

10000/T (K)

150mTorr

Gd : Ba : Cu ≈ 1 : 1 : 2.5

Precursor composition

Electronic Materials & Devices Laboratory Seoul National UniversityDepartment of Material Science & Engineering

sampleJc (MA/m3)

self-field 1T 3T 5T

840°C65K 5.6 0.84 0.26 0.09

77K 3.2 0.25 0.01 3.9X10-5

860°C65K 5.3 0.67 0.19 0.064

77K 2.9 0.19 0.009 0.0012

880°C65K 3.6 0.4 0.11 0.027

77K 1.9 0.11 0.0032 2.0X10-5

0 1 2 3 4 510

1

102

103

104

105

106

840oC, 77K

840oC, 65K

860oC, 77K

860oC, 65K

880oC, 77K

880oC, 65K

77K

65K

JC (

A/c

m2)

m0H (T)

H // c

Magnetic field dependence of Jc & Pinning force density (Fp)

0 1 2 3 4 50

2

4

6

8

10 840

oC, 77K

840oC, 65K

860oC, 77K

860oC, 65K

880oC, 77K

880oC, 65K

77K

65K

Pin

nin

g f

orc

e d

en

sity

(G

N/m

3)

m0H (T)

sampleFp,max= Jc ⅹ B

(GN/m3)

840°C65K 8.8 (1.8T)

77K 2.8 (0.4T)

860°C65K 7.1 (1.6T)

77K 2.24 (0.35T)

880°C65K 4.2 (1.6T)

77K 1.3 (0.25T)

S.M. Choi et al., IEEE Trans. on Appl. Supercond. 2015


0 30 60 90 120 150 180 210 240

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0 840

oC

860oC

880oC

H//ab77K, 1T

Angle (deg.)

Jc (

MA

/cm

2)

0 30 60 90 120 150 180 210 2400.0

0.5

1.0

1.5

2.0

2.5

840oC

860oC

880oC

H//ab65K, 3T

Angle (deg.)

Jc (

MA

/cm

2)

Angular dependence of Jc

The GdBCO CCs by RCE-DR show a sharp Jc peak at θ = 90° (H//ab).

A small broad peak of Jc near θ = 180° (H//c) is also observed.

The sample grown at 840°C shows higher Jc values compared with those of samples

grown at higher temperatures.



20 25 30 35 40 45 50 55 60 65 70

(00

8)

(10

3)

Ba

Cu

O2

2 (Cu K)

Gd

2O

3(6

22

)

Gd

2O

3(4

40

)

840oC

(150mTorr)

880oC

(150mTorr)

Gd

2O

3(4

00

)

Gd

2O

3(2

22

) (00

7)(0

06

)

(00

5)

(00

4)

Ni

(11

1)

Ni

(00

2)

Cu

O(2

02

)

Mg

O(2

00

)

Cu

O (

-11

1)

(00

3)

Inte

nsi

ty (

Arb

.un

it)

860oC

(150mTorr)

XRD θ-2θ scans and texture analysis of GdBCO CCs

840 860 880

1

2

32

3

4

5

Temperature (oC)

(

deg

.)(

deg

.)

Δ () Δω ()

840 C 4.28 2.53

860 C 3.37 1.54

880 C 2.6 1.04

The GdBCO (00l) reflections indicate that the GdBCO films are highly c-axis oriented. The

second phases such as Gd2O3 and CuO peaks are also observed in addition to the substrate peaks.

A small GdBCO (103) peak is observed for the film prepared at 840 °C, suggesting that a small

amount of randomly oriented GdBCO grains exist in the film.

S.M. Choi et al., IEEE Trans. on Appl. Supercond. (accepted)


0 . 2 µ m0 . 2 µ m 0 . 2 µ m

840C 860C 880C

Cross-sectional TEM images

The average particle sizes of Gd2O3 are 126.5 ± 42.6 nm in the 840°C sample, 171.4

± 53.1 nm in the 860°C sample, and 217.8 ± 49.4 nm in the 880°C sample.



20mm 20mm

20mm 20mm 20mm

20mm

840 ºC sample

Polarized light microscope images

S.M. Choi et al., IEEE Trans. on Appl. Supercon. (accepted)


EBSD analysis data of 840 °C sample

4μm

Image quality map Inverse pole figure image

5μm

Image quality map Inverse pole figure image

S.M. Choi et al., IEEE Trans. on Appl. Supercon. (accepted)


For the nominal composition of Gd:Ba:Cu = 1:1:2.5

Decreased intermediate

PO2 zone below 800oC!!!


PM3 Zone 780 oC

SEM micrographs of the surface morphology

X 5k X 10k

Normal process


PM3 Zone 780 oC – TEM analysis

1 um1 um 0.5 um0.5 um

Particle size (Gd2O3) : 105.1 ± 95.6 nm


PM3 Zone 780 oC – EDX analysis

Increased pinning properties by composition control

(1.0 1.4 3.6)

Compositions studied here give a more

Cu-rich liquid which influences growth

kinetics and pinning

There will be Gd2O3 particles in all GdBCO samples but a

specific precursor composition, PO2, and T are key factors

determining their performance. It is clear that very fine Gd2O3

nanoparticles result in the highest performance.

Driscoll et al., AIP Materials 2, 086103 (2014)


In-field Performance (77 K)

(By Dr. Izumi, ISS2012(Japan))

RCE-DR GdBCO w/o APC (C,D composition)

SuNAM’s

present

: 1.4 um

Only with composition control in RCE-

DR process, we can achieve strong

pinnings without APCs.

Driscoll et al., AIP Materials 2, 086103 (2014)



Stability phase diagrams of REBCO (RE: Y, Gd, Sm)

(a) T.B. Lindemer et al.,

Physica C 178 (1991)

93-104.

(b) J.L. MacManus-Driscoll et

al., Physica C 241 (1995)

401-413.

(c) K. Iida et al., Supercond.

Sci. Technol. 19 (2006)

S478-S485.

(d) J.W. Lee et al.,

J. Alloys Compd. 602,

(2014) 78-86.

(e) C. Wende et al.,

J. Alloys Compd. 381

(2004) 320–326.

(f) J.H. Song, Master thesis,

Seoul National University

(2014)


[1 PO2 200 mTorr]

Y123 ↔ Y2O3 + Y132 + L

log PO2 (Torr) = = 9.787 − 11,783/T(K)

[250 PO2 900 mTorr]

Y123 ↔ Y211 + Y132 + L

log PO2 (Torr) = 12.670 − 15,276/T(K)

[20 PO2 200 mTorr]

Y123 ↔ Y211 + Y132 + BaCu2O2 (S)

[100 PO2 500 mTorr]

Y123 ↔ Y211 + Y132 + BaCu2O2 (L)

Equilibrium decomposition products of Y123:

Comparison with previous reports on YBCO




diagrams in low PO2


Defect generation by the post-annealing process

Defect generation by employing the dopants



Why post-annealing?


34

34

x

The post-annealing conditions


Holding

time

Tc, zero

(K)

Ref. 89.9

5 min 93.7

10 min 89.1

30 min 88.4

120 min 87.0

80 82 84 86 88 90 92 94 96 98 100 102 1040

100

200

300

400

500

600

700

800

900

0 50 100 150 200 250 3000

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

Resi

stiv

ity (mcm

)

Temperature (K)

Res

isti

vit

y (m

cm)

Temperature (K)

reference

5min

10min

30min

120min

The Tc, zero value of the sample annealed for 5 min is increased to ~ 94 K.

ρ-T curves & magnetic Jc-B curves

Annealed @800C in the PO2 of 300 mTorr

J.W. Lee et al. (submitted to IEEE Trans. on Appl. Supercond.)


Magnetic Jc-B curvesJ.W. Lee et al. (submitted to IEEE Trans. on Appl. Supercond.)


Angular dependence of Jc & Microstructure analyses

0 20 40 60 80 100 120 140 160 180 200 220

0.4

0.6

0.8

1.0 B//ab

Jc (

MA

/cm

2)

Angle (deg.)

Ref.

After annealing

0 20 40 60 80 100 120 140 160 180 200 220

0.1

0.2

0.3

0.4

0.5

Ref.

After annealing

B//ab

Jc (

MA

/cm

2)

Angle (deg.)

77K, 1T 77K, 3T

2 0 0 n m2 0 0 n m

Reference Post-annealed

2 0 0 n m2 0 0 n m

Post-annealed

1 0 0 n m1 0 0 n m

Post-annealed

c-axis

J.W. Lee et al. (submitted to IEEE Trans. on Appl. Supercond.)




diagrams in low PO2


Defect generation by the post-annealing process

Defect generation by employing the dopants


BaSnO3 addition

0 20 40 60 80 1000

100

200

300

400

500

600

700@ 77 K, self-field

10 wt% Sn doped GdBCO

I C

(A

/12m

m)

Length (m)

(From SuNAM)

BaSnO3 addition

In-field performance

0 30 60 900

100

200

300

400

B//cB//ab

10 wt% Sn doped GdBCO (IC,S.F.

=547 A/12mm)

20 wt% Sn doped GdBCO (IC,S.F.

=275 A/12mm)

Undoped GdBCO (IC,S.F.

=720 A/12mm)

I C

(A

/12m

m)

Angle (degree)

@ 77 K, 6300 G

(From SuNAM)


41

41

IV. Summary

• The flux pinning properties of GdBCO CCs could be improved by

controlling the conversion temperature of the amorphous precursor film

from Gd2O3 + liquid to the GdBCO phase due to the refinement of Gd2O3

particles trapped in the GdBCO matrix.

• Both Jc-B curves and the angular dependence of Jc of GdBCO CCs reveal

that the flux pinning can be improved by the post-annealing process and

also by the dopant like Sn.

• Further R&D is under progress to develop higher performance REBCO CCs

exceeding GdBCO, which include Y or other RE elements and their binary

or ternary mixture, in addition to a strong effort to improve the pinning

properties of GdBCO CC.

• Our group started R&D on a multicore REBCO tape similar to the BiSCCO

tape (Industry Fund from POSCO).


Thank you very much for your kind attention

recent advances in rebco coated conductors via …sang...electronic materials & devices...

Documents