YBCO/IBAD/Inconel coated conductor withend-to-end critical current of 96 A at 75 K

Los AlamosMaterials Science and Technology

STC: Superconductivity Technology Center

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Position on tape (cm)

Critical current (A)

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Critical current density (MA/cm

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Field Dependence ofCritical Current Density

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YBCO H(||)c (4K)YBCO H||c (75K)YBCO H||ab (75K)BSCCO H||c (75K)

H(T)

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Bending Test

Compression

Sample ATension

Sample BTension after

Sample B

compression test

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Strain (%)0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

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@ 75 K36mmSample16mm

Progress towards higher Ic in longer lengths

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Tape length (cm)

Critical current (Amps)75 K

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1995 (batch mode)

The Jc reduction above 1.5 m appears related to an increase in surface roughness with YBCO thickness ...

Superconductivity Technology Center

0.39 m 1.5 m 3.0 m

Jc = 2.3 MA/cm2

calc. Ic = 90 A/cmJc = 1.5 MA/cm2

calc. Ic = 225 A/cmJc = 0.6 MA/cm2

calc. Ic = 180 A/cm

Ion milling shows that a multilayer structure allows Ic to continue to increase at thickness levels above 1.5 m

Superconductivity Technology Center

75 K -- Bridge dimensions: 150 m x 5 mm 0

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Superconductor thickness ( m)

Calculated critical current

( / - )A cm width YBCO single layer

(Y-Sm-Y-Sm-Y) multilayer

Rate of increase: 60 A/cm-width for each additional micron of superconductor thickness

Y123-Sm123 Multilayers Enabled Thicker Films with Higher Critical Currents

Superconductivity Technology Center

Y- Sm-Y- Sm-Y multilayer

YBCO thickness: ~1.1 m

SBCO thickness: ~ 0.2 m

Total thickness: 3.7 m

Jc: 1.1 MA/cm2 (75 K)

Calculated Ic: 405 A/cm-width

For comparison, Jc of a 3.7 m YBCO single-layer: 0.4 MA/cm2

Silver contactYBCOSm1Ba2Cu3O7-

CeO2

IBAD YSZInconel

Bridge dimensions: ~ 200 m x 5 mm

Modified superconductor processes push the Ic well beyond the 200 A/cm-width “barrier” to over 500 A/cm

Superconductivity Technology Center

Substrate: Inconel 625 with IBAD YSZ

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YBCO thickness ( m)

( /Critical current density MA cm

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Ic for 1 cm wide tape

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75 K -- bridges 200 m x 5 mm

IBAD MgO template forms at ~ 10 nm thickness - approximately 100 times thinner/faster than for IBAD YSZ

Los AlamosSuperconductivity Technology Center

0.1 µm

IBAD texture evolution vs. thickness

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Phi

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IBAD texture evolution vs. thickness

YBCO

YSZ

Epi MgO

Si3N4

Inconel 625

Y2O3

IBAD MgO

Ic (75K) = 42 A