Pinning in Al doped YBCO bulk superconductors

V Antal 12 M Kaňuchovaacute 1 M Šefčikovaacute 1 P Diko 13

M Eisterer 2 N Houmlrhager2 M Zehetmayer2 H W Weber 2

X Chaud 3

1 Material Physics Laboratory Institute of Experimental Physics SAS Košice Slovakia

2 Atomic Institute of the Austrian Universities Vienna Austria

3 CNRSCRETA 25 Avenue des Martyrs 38042 Grenoble Cedex 9 France

Motivation

Cu substitutions in TSMG YBCO bulk superconductors

Zn Krabbes et al Physica C 2000 Li Shlyk et al Appl Phys Lett 2002Pd Ni Shlyk et al Physica C 2002Fe Shlyk et al Journal of Physics 2006 Zn Ni Co Ga Zhou Scruggs Salama SUST 2006 Ag T Nakashima Journal of Physics 2008

Al substitution was not studied in YBCO bulks so far

Al

Al substitutes in CuO chains (Re = Y)

Al - doped TSMG YBCO bulk

Preparation of Al ndash doped YBCO bulk superconductors

Time - temperature program for the top seeded melt growth (TSMG) process

Samples YBa2Cu3O7 + 025Y2O3 + 05 wt CeO2 + Al2O3 YBa2(Cu3-xAlx)O7 (x = 00025 0005 001 002 005)

TSMG pellets = 20 mm Sm 123 seeds chamber furnace in air

The samples were heated to 800 degC in flowing O2 atmosphere and kept there for 2 hrs then cooled to 400 degC and held at this temperature for 240 hrs then cooled down to room temperature

1) Standard oxygenation (SO)

2) Annealing in flowing argonThe samples were heated to 800 degC in flowing Ar atmosphere and annealed there for 2 hrs then cooled to room temperature After annealing in Ar the samples were heated to 400 degC in flowing O2 atmosphere and held there for 240 hrs then cooled down to room temperature

3) High pressure oxygenation (HPO)The samples were oxygenated under an oxygen pressure of 160 bars at 750 degC for 24 hrs with progressively increasing oxygen pressure

Different methods of oxygenation

Typical dimensions of the samples for oxygenation and magnetization measurements

c - axis

Magnetization measurementsVSM with magnetic fields of up to 5 Teslaat a constant sweep rate of 025 Tmin applied field parallel to the c-axis

)31(

4)()(

abb

BmBJ i

c

)(2

1 mmmi cba ba

Bean model

Magnetization measurements

Checking samples for homogeneityby trapped field scanning

Critical current densities in samples treated by SO and annealing in argon

Annealed in argonStandard oxygenation

x = 00025 (SO) x = 005 (Ar)Jc asymp 18104 Acm2 μ0H = 1 T

Effect of Al ndash doping and HPO on critical current density

HPO

HPO T = 77 Kx = 00025Jc peakasymp 53104 Acm2 μ0 Hp asymp 137 T

SO T = 77 Kx = 00025Jc peakasymp 18104 Acm2 μ0 Hp asymp 089 T

(55 ~80 K)

Suppression of oxygenation cracks by high pressure oxygenation

c

ab

c

ab

c- and ab-macrocracks formedin TSMG YBa2(Cu3-xAlx)O7 during standard oxygenation at 400 degC (SO)

ab-microcracks in TSMG YBa2(Cu3-xAlx)O7 oxygenated at 750 degC under an oxygen pressure of 160 bars (HPO)

c-MAC

ab-MAC

c-MAC

Pinning force density

HPO

HPO 158 le p le 211 710 le q le 828HPO 158 le p le 211 710 le q le 828

SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344

Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344

[EJ Kramer J Appl Phys 44 1360 (1973)]

pprc bbBBF )1()( 2

2 cBBb

q

fppfpn b

qp

bF

11

p q gt 0 bfp=Hmax Ha

Fn=Fp Fmax

[M Jirsa et al Physica C 338 235 (2000)]

77 K

Magnetization relaxation measurements

td

dM

MS

ln

1

0

at μ0H = 1 T and T = 77 KS (SO) = 00911 asymp 911S (HPO) = 00568 asymp 568

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

Motivation

Cu substitutions in TSMG YBCO bulk superconductors

Zn Krabbes et al Physica C 2000 Li Shlyk et al Appl Phys Lett 2002Pd Ni Shlyk et al Physica C 2002Fe Shlyk et al Journal of Physics 2006 Zn Ni Co Ga Zhou Scruggs Salama SUST 2006 Ag T Nakashima Journal of Physics 2008

Al substitution was not studied in YBCO bulks so far

Al

Al substitutes in CuO chains (Re = Y)

Al - doped TSMG YBCO bulk

Preparation of Al ndash doped YBCO bulk superconductors

Time - temperature program for the top seeded melt growth (TSMG) process

Samples YBa2Cu3O7 + 025Y2O3 + 05 wt CeO2 + Al2O3 YBa2(Cu3-xAlx)O7 (x = 00025 0005 001 002 005)

TSMG pellets = 20 mm Sm 123 seeds chamber furnace in air

The samples were heated to 800 degC in flowing O2 atmosphere and kept there for 2 hrs then cooled to 400 degC and held at this temperature for 240 hrs then cooled down to room temperature

1) Standard oxygenation (SO)

2) Annealing in flowing argonThe samples were heated to 800 degC in flowing Ar atmosphere and annealed there for 2 hrs then cooled to room temperature After annealing in Ar the samples were heated to 400 degC in flowing O2 atmosphere and held there for 240 hrs then cooled down to room temperature

3) High pressure oxygenation (HPO)The samples were oxygenated under an oxygen pressure of 160 bars at 750 degC for 24 hrs with progressively increasing oxygen pressure

Different methods of oxygenation

Typical dimensions of the samples for oxygenation and magnetization measurements

c - axis

Magnetization measurementsVSM with magnetic fields of up to 5 Teslaat a constant sweep rate of 025 Tmin applied field parallel to the c-axis

)31(

4)()(

abb

BmBJ i

c

)(2

1 mmmi cba ba

Bean model

Magnetization measurements

Checking samples for homogeneityby trapped field scanning

Critical current densities in samples treated by SO and annealing in argon

Annealed in argonStandard oxygenation

x = 00025 (SO) x = 005 (Ar)Jc asymp 18104 Acm2 μ0H = 1 T

Effect of Al ndash doping and HPO on critical current density

HPO

HPO T = 77 Kx = 00025Jc peakasymp 53104 Acm2 μ0 Hp asymp 137 T

SO T = 77 Kx = 00025Jc peakasymp 18104 Acm2 μ0 Hp asymp 089 T

(55 ~80 K)

Suppression of oxygenation cracks by high pressure oxygenation

c

ab

c

ab

c- and ab-macrocracks formedin TSMG YBa2(Cu3-xAlx)O7 during standard oxygenation at 400 degC (SO)

ab-microcracks in TSMG YBa2(Cu3-xAlx)O7 oxygenated at 750 degC under an oxygen pressure of 160 bars (HPO)

c-MAC

ab-MAC

c-MAC

Pinning force density

HPO

HPO 158 le p le 211 710 le q le 828HPO 158 le p le 211 710 le q le 828

SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344

Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344

[EJ Kramer J Appl Phys 44 1360 (1973)]

pprc bbBBF )1()( 2

2 cBBb

q

fppfpn b

qp

bF

11

p q gt 0 bfp=Hmax Ha

Fn=Fp Fmax

[M Jirsa et al Physica C 338 235 (2000)]

77 K

Magnetization relaxation measurements

td

dM

MS

ln

1

0

at μ0H = 1 T and T = 77 KS (SO) = 00911 asymp 911S (HPO) = 00568 asymp 568

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

Al - doped TSMG YBCO bulk

Preparation of Al ndash doped YBCO bulk superconductors

Time - temperature program for the top seeded melt growth (TSMG) process

Samples YBa2Cu3O7 + 025Y2O3 + 05 wt CeO2 + Al2O3 YBa2(Cu3-xAlx)O7 (x = 00025 0005 001 002 005)

TSMG pellets = 20 mm Sm 123 seeds chamber furnace in air

The samples were heated to 800 degC in flowing O2 atmosphere and kept there for 2 hrs then cooled to 400 degC and held at this temperature for 240 hrs then cooled down to room temperature

1) Standard oxygenation (SO)

2) Annealing in flowing argonThe samples were heated to 800 degC in flowing Ar atmosphere and annealed there for 2 hrs then cooled to room temperature After annealing in Ar the samples were heated to 400 degC in flowing O2 atmosphere and held there for 240 hrs then cooled down to room temperature

3) High pressure oxygenation (HPO)The samples were oxygenated under an oxygen pressure of 160 bars at 750 degC for 24 hrs with progressively increasing oxygen pressure

Different methods of oxygenation

Typical dimensions of the samples for oxygenation and magnetization measurements

c - axis

Magnetization measurementsVSM with magnetic fields of up to 5 Teslaat a constant sweep rate of 025 Tmin applied field parallel to the c-axis

)31(

4)()(

abb

BmBJ i

c

)(2

1 mmmi cba ba

Bean model

Magnetization measurements

Checking samples for homogeneityby trapped field scanning

Critical current densities in samples treated by SO and annealing in argon

Annealed in argonStandard oxygenation

x = 00025 (SO) x = 005 (Ar)Jc asymp 18104 Acm2 μ0H = 1 T

Effect of Al ndash doping and HPO on critical current density

HPO

HPO T = 77 Kx = 00025Jc peakasymp 53104 Acm2 μ0 Hp asymp 137 T

SO T = 77 Kx = 00025Jc peakasymp 18104 Acm2 μ0 Hp asymp 089 T

(55 ~80 K)

Suppression of oxygenation cracks by high pressure oxygenation

c

ab

c

ab

c- and ab-macrocracks formedin TSMG YBa2(Cu3-xAlx)O7 during standard oxygenation at 400 degC (SO)

ab-microcracks in TSMG YBa2(Cu3-xAlx)O7 oxygenated at 750 degC under an oxygen pressure of 160 bars (HPO)

c-MAC

ab-MAC

c-MAC

Pinning force density

HPO

HPO 158 le p le 211 710 le q le 828HPO 158 le p le 211 710 le q le 828

SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344

Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344

[EJ Kramer J Appl Phys 44 1360 (1973)]

pprc bbBBF )1()( 2

2 cBBb

q

fppfpn b

qp

bF

11

p q gt 0 bfp=Hmax Ha

Fn=Fp Fmax

[M Jirsa et al Physica C 338 235 (2000)]

77 K

Magnetization relaxation measurements

td

dM

MS

ln

1

0

at μ0H = 1 T and T = 77 KS (SO) = 00911 asymp 911S (HPO) = 00568 asymp 568

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

The samples were heated to 800 degC in flowing O2 atmosphere and kept there for 2 hrs then cooled to 400 degC and held at this temperature for 240 hrs then cooled down to room temperature

1) Standard oxygenation (SO)

2) Annealing in flowing argonThe samples were heated to 800 degC in flowing Ar atmosphere and annealed there for 2 hrs then cooled to room temperature After annealing in Ar the samples were heated to 400 degC in flowing O2 atmosphere and held there for 240 hrs then cooled down to room temperature

3) High pressure oxygenation (HPO)The samples were oxygenated under an oxygen pressure of 160 bars at 750 degC for 24 hrs with progressively increasing oxygen pressure

Different methods of oxygenation

Typical dimensions of the samples for oxygenation and magnetization measurements

c - axis

Magnetization measurementsVSM with magnetic fields of up to 5 Teslaat a constant sweep rate of 025 Tmin applied field parallel to the c-axis

)31(

4)()(

abb

BmBJ i

c

)(2

1 mmmi cba ba

Bean model

Magnetization measurements

Checking samples for homogeneityby trapped field scanning

Critical current densities in samples treated by SO and annealing in argon

Annealed in argonStandard oxygenation

x = 00025 (SO) x = 005 (Ar)Jc asymp 18104 Acm2 μ0H = 1 T

Effect of Al ndash doping and HPO on critical current density

HPO

HPO T = 77 Kx = 00025Jc peakasymp 53104 Acm2 μ0 Hp asymp 137 T

SO T = 77 Kx = 00025Jc peakasymp 18104 Acm2 μ0 Hp asymp 089 T

(55 ~80 K)

Suppression of oxygenation cracks by high pressure oxygenation

c

ab

c

ab

c- and ab-macrocracks formedin TSMG YBa2(Cu3-xAlx)O7 during standard oxygenation at 400 degC (SO)

ab-microcracks in TSMG YBa2(Cu3-xAlx)O7 oxygenated at 750 degC under an oxygen pressure of 160 bars (HPO)

c-MAC

ab-MAC

c-MAC

Pinning force density

HPO

HPO 158 le p le 211 710 le q le 828HPO 158 le p le 211 710 le q le 828

SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344

Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344

[EJ Kramer J Appl Phys 44 1360 (1973)]

pprc bbBBF )1()( 2

2 cBBb

q

fppfpn b

qp

bF

11

p q gt 0 bfp=Hmax Ha

Fn=Fp Fmax

[M Jirsa et al Physica C 338 235 (2000)]

77 K

Magnetization relaxation measurements

td

dM

MS

ln

1

0

at μ0H = 1 T and T = 77 KS (SO) = 00911 asymp 911S (HPO) = 00568 asymp 568

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

Magnetization measurementsVSM with magnetic fields of up to 5 Teslaat a constant sweep rate of 025 Tmin applied field parallel to the c-axis

)31(

4)()(

abb

BmBJ i

c

)(2

1 mmmi cba ba

Bean model

Magnetization measurements

Checking samples for homogeneityby trapped field scanning

Critical current densities in samples treated by SO and annealing in argon

Annealed in argonStandard oxygenation

x = 00025 (SO) x = 005 (Ar)Jc asymp 18104 Acm2 μ0H = 1 T

Effect of Al ndash doping and HPO on critical current density

HPO

HPO T = 77 Kx = 00025Jc peakasymp 53104 Acm2 μ0 Hp asymp 137 T

SO T = 77 Kx = 00025Jc peakasymp 18104 Acm2 μ0 Hp asymp 089 T

(55 ~80 K)

Suppression of oxygenation cracks by high pressure oxygenation

c

ab

c

ab

c- and ab-macrocracks formedin TSMG YBa2(Cu3-xAlx)O7 during standard oxygenation at 400 degC (SO)

ab-microcracks in TSMG YBa2(Cu3-xAlx)O7 oxygenated at 750 degC under an oxygen pressure of 160 bars (HPO)

c-MAC

ab-MAC

c-MAC

Pinning force density

HPO

HPO 158 le p le 211 710 le q le 828HPO 158 le p le 211 710 le q le 828

SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344

Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344

[EJ Kramer J Appl Phys 44 1360 (1973)]

pprc bbBBF )1()( 2

2 cBBb

q

fppfpn b

qp

bF

11

p q gt 0 bfp=Hmax Ha

Fn=Fp Fmax

[M Jirsa et al Physica C 338 235 (2000)]

77 K

Magnetization relaxation measurements

td

dM

MS

ln

1

0

at μ0H = 1 T and T = 77 KS (SO) = 00911 asymp 911S (HPO) = 00568 asymp 568

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

Critical current densities in samples treated by SO and annealing in argon

Annealed in argonStandard oxygenation

x = 00025 (SO) x = 005 (Ar)Jc asymp 18104 Acm2 μ0H = 1 T

Effect of Al ndash doping and HPO on critical current density

HPO

HPO T = 77 Kx = 00025Jc peakasymp 53104 Acm2 μ0 Hp asymp 137 T

SO T = 77 Kx = 00025Jc peakasymp 18104 Acm2 μ0 Hp asymp 089 T

(55 ~80 K)

Suppression of oxygenation cracks by high pressure oxygenation

c

ab

c

ab

c- and ab-macrocracks formedin TSMG YBa2(Cu3-xAlx)O7 during standard oxygenation at 400 degC (SO)

ab-microcracks in TSMG YBa2(Cu3-xAlx)O7 oxygenated at 750 degC under an oxygen pressure of 160 bars (HPO)

c-MAC

ab-MAC

c-MAC

Pinning force density

HPO

HPO 158 le p le 211 710 le q le 828HPO 158 le p le 211 710 le q le 828

SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344

Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344

[EJ Kramer J Appl Phys 44 1360 (1973)]

pprc bbBBF )1()( 2

2 cBBb

q

fppfpn b

qp

bF

11

p q gt 0 bfp=Hmax Ha

Fn=Fp Fmax

[M Jirsa et al Physica C 338 235 (2000)]

77 K

Magnetization relaxation measurements

td

dM

MS

ln

1

0

at μ0H = 1 T and T = 77 KS (SO) = 00911 asymp 911S (HPO) = 00568 asymp 568

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

Effect of Al ndash doping and HPO on critical current density

HPO

HPO T = 77 Kx = 00025Jc peakasymp 53104 Acm2 μ0 Hp asymp 137 T

SO T = 77 Kx = 00025Jc peakasymp 18104 Acm2 μ0 Hp asymp 089 T

(55 ~80 K)

Suppression of oxygenation cracks by high pressure oxygenation

c

ab

c

ab

c- and ab-macrocracks formedin TSMG YBa2(Cu3-xAlx)O7 during standard oxygenation at 400 degC (SO)

ab-microcracks in TSMG YBa2(Cu3-xAlx)O7 oxygenated at 750 degC under an oxygen pressure of 160 bars (HPO)

c-MAC

ab-MAC

c-MAC

Pinning force density

HPO

HPO 158 le p le 211 710 le q le 828HPO 158 le p le 211 710 le q le 828

SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344

Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344

[EJ Kramer J Appl Phys 44 1360 (1973)]

pprc bbBBF )1()( 2

2 cBBb

q

fppfpn b

qp

bF

11

p q gt 0 bfp=Hmax Ha

Fn=Fp Fmax

[M Jirsa et al Physica C 338 235 (2000)]

77 K

Magnetization relaxation measurements

td

dM

MS

ln

1

0

at μ0H = 1 T and T = 77 KS (SO) = 00911 asymp 911S (HPO) = 00568 asymp 568

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

Suppression of oxygenation cracks by high pressure oxygenation

c

ab

c

ab

c- and ab-macrocracks formedin TSMG YBa2(Cu3-xAlx)O7 during standard oxygenation at 400 degC (SO)

ab-microcracks in TSMG YBa2(Cu3-xAlx)O7 oxygenated at 750 degC under an oxygen pressure of 160 bars (HPO)

c-MAC

ab-MAC

c-MAC

Pinning force density

HPO

HPO 158 le p le 211 710 le q le 828HPO 158 le p le 211 710 le q le 828

SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344

Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344

[EJ Kramer J Appl Phys 44 1360 (1973)]

pprc bbBBF )1()( 2

2 cBBb

q

fppfpn b

qp

bF

11

p q gt 0 bfp=Hmax Ha

Fn=Fp Fmax

[M Jirsa et al Physica C 338 235 (2000)]

77 K

Magnetization relaxation measurements

td

dM

MS

ln

1

0

at μ0H = 1 T and T = 77 KS (SO) = 00911 asymp 911S (HPO) = 00568 asymp 568

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

Pinning force density

HPO

HPO 158 le p le 211 710 le q le 828HPO 158 le p le 211 710 le q le 828

SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344SO 107 le p le 138 286 le q le 451for SO x = 00025 p = 186 q = 344

Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344Argon 112 le p le 125 063 le q le 093for x = 005 p = 183 q = 344

[EJ Kramer J Appl Phys 44 1360 (1973)]

pprc bbBBF )1()( 2

2 cBBb

q

fppfpn b

qp

bF

11

p q gt 0 bfp=Hmax Ha

Fn=Fp Fmax

[M Jirsa et al Physica C 338 235 (2000)]

77 K

Magnetization relaxation measurements

td

dM

MS

ln

1

0

at μ0H = 1 T and T = 77 KS (SO) = 00911 asymp 911S (HPO) = 00568 asymp 568

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

Magnetization relaxation measurements

td

dM

MS

ln

1

0

at μ0H = 1 T and T = 77 KS (SO) = 00911 asymp 911S (HPO) = 00568 asymp 568

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

Conclusions

- Al substitution induces a peak effect in TSMG YBCO bulks

- Annealing in Ar caused significant changes in both Tc and pinning behaviour

- High pressure oxygenation preserves the peak effect caused by Al substitution

- Oxygenation cracks are eliminated by high pressure oxygenation Jc increases by a factor of ~ 3

The results were presented at P Diko et al ldquoInternational Conference on Superconductivity and Magnetism (ICSM 2008) 25-29 August 2008 Side AntalyaTurkey V Antal et al 2nd NESPA meeting 2- 4102008 Rust Austria

Publication accepted in Journal of Physics Conference Series (2009)

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12

Ďakujem za pozornosť

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Slide 11
• Slide 12