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High speed production of YBCO precursor films by advanced TFA-MOD process
Physica C 469 (2009) 1329–1331
Contents lists available at ScienceDirect
Physica C journal homepage: www.elsevier.com/locate/physc
High speed production of YBCO precursor films by advanced TFA-MOD process H. Ichikawa *, K. Nakaoka, M. Miura, Y. Sutoh, T. Nakanishi, A. Nakai, M. Yoshizumi, T. Izumi, Y. Shiohara Superconductivity Research Laboratory, ISTEC, 1-10-13, Shinonome, Koto-Ku, Tokyo 135-0062, Japan
a r t i c l e
i n f o
Article history: Available online 28 May 2009 PACS: 74.78. w 74.72.Bk 74.25.Sv Keywords: YBCO TFA-MOD Calcination
a b s t r a c t YBa2Cu3O7 y (YBCO) long tapes derived from the metal-organic deposition (MOD) method using the starting solution containing trifluoroacetate (TFA) have been developed with high critical currents (Ic) over 200 A/cm-width. However, high speed production of YBCO films is simultaneously necessary to satisfy the requirements of electric power device applications in terms of cost and the amounts of the tapes. In this work, we developed a new TFA-MOD starting solution using F-free salt of Y, TFA salt of Ba and Cu-Octylate for application to the coating/calcination process and discussed several issues by using the Multi-turn (MT) Reel-to-Reel (RTR) system calcination furnace for the purpose of high throughput without degradation of the properties. The coating system was improved for uniform deposition qualities in both longitudinal and transversal directions. YBCO films using the new starting solution at the traveling rate of 10 m/h in coating/calcination by the MT-RTR calcination furnace showed the values of the critical current density of 1.6 MA/cm2 as thick as 1.5 lm at 77 K under the self fields after firing at the high heating rate in the crystallization. Ó 2009 Elsevier B.V. All rights reserved.
1. Introduction YBa2Cu3O7 y (YBCO) coated conductors (CCs) with high critical current density (Jc) under the self-fields as well as the external magnetic field would be expected for application to some electric power devices such as power cables, Superconducting Magnetic Energy Storage (SMES) and transformers. The metal-organic deposition (MOD) method using the starting solution containing trifluoroacetate (TFA) salts of yttrium, barium and copper [2] is one of the most promising methods for fabrication of long-length YBCO tapes [1,3]. A 56 m long-tape of YBCO derived from the TFA-MOD process were developed to have the Ic value of 250 A/ cm-width using a conventional starting solution including TFA salt of Y, TFA salt of Ba, naphthenic acid of Cu with the Ba-deficient composition (Y:Ba:Cu = 1:1.5:3) [4–6]. However, there were two serious problems to be solved including the evolution of tar and different qualities in the different batch solutions since the naphthenic acid is extracted from the natural petroleum source. So, we developed a new starting solution including TFA salt of Y, TFA salt of Ba, Cu-Octylate with the Ba-deficient composition (Y:Ba:Cu = 1:1.5:3) which is called as ‘‘the advanced solution”. Although the advanced solution solved the above-mentioned problems, there is still an issue for higher speed production without degradation of properties for realizing low cost. In order to improve production speed, another starting solution was developed based on the similar concept to the advanced solution i.e. * Corresponding author. Tel.: +81 3 3536 5711; fax: +81 3 3536 8311. E-mail address: [email protected] (H. Ichikawa). 0921-4534/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.physc.2009.05.023
reduction of the fluorine content in the solution, which is called as the further advanced starting solution (F-advanced). The films derived from the F-advanced solution revealed the high Jc values of over 2.5 MA/cm2 in the short substrates. In this study, we investigated the influences of the maximum temperature and the heating rate in the calcination heat treatment step in order to apply the F-advanced solution to the MT-RTR calcination furnace for high production. We evaluated the properties of precursor films fired at high heating rate in the crystallization step. 2. Experimental The starting solutions were prepared by dissolving F-free of Y for the F-advanced solution or TFA salt of Y for the advanced one, TFA salt of Ba and Cu-Octylate with a cationic ratio of Y:Ba:Cu = 1:1.5:3 into the organic solvent. The stating solution was coated on the CeO2 buffered IBAD-Gd2Zr2O7/Hastelloy substrates by the dip coating method followed by heating up to 420–510 °C in an O2 gas flow using the Multi-turn (MT) Reel-toReel (RTR) system calcination furnace which has a typical temperature gradient of 25 °C/min. The film thickness per single coating was controlled by viscosity of the solution. Finally these samples were heated to 740–800 °C in the mixed humid (P(H2O) = 15 vol.) gas flow of argon and oxygen P(O2) = 10–102 Pa. The final thickness of the YBCO superconductor films was about 1.0–1.6 lm. The precursor films and the crystallized YBCO films were examined by Xray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In addition, the chemical
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Fig. 1. Properties of the YBCO films derived from the advanced solution and the Fadvanced one at different traveling rates in the coating and calcination step.
Fig. 2. Relationship between the Jc values in the films from the F-advanced solution and the maximum temperature of calcinations (T Cmax ) at the traveling rate of 10 m/h in coating and calcination after firing at the heating rate of 70 °C/min.
composition analysis of these films and the film thickness were measured by Inductively Coupled Plasma (ICP). The critical current (Ic) of the crystallized films was measured at 77 K under the selffields by the DC four-probe method with the criterion of voltage of 1 lV/cm. 3. Results and discussion Fig. 1 shows the property of the YBCO films derived from the advanced solution and the F-advanced one at the traveling rate of coating and calcination, 2 m/h, 5 m/h and 10 m/h, respectively. The films from the F-advanced starting solution maintained the high Jc values up to the high speed traveling rate of 10 m/h in the coating and calcination step, while the films from the advanced one revealed degradation of Jc values with increasing the traveling rate. The degradation of Jc values was thought to be due to the incomplete precursor films because of the high heating rate and deficiency in calcination times. We found that the F-advanced solution was appropriate to fabricate superconducting films with high Jc values at the high traveling rate of 10 m/h in the coating and calcination step and at the low heating rate of 2 °C/min in the crystallization step. Table 1 shows the growth conditions and the superconducting properties of the films from both the advanced and the F-advanced solutions. It was found that there are large difference in the heating rates of 2 and 70 °C/min in the crystallization step for the Jc values especially in the films coated and calcined at the high traveling rate. The precursor films coated and calcined at the traveling rate of 10 m/h using the F-advanced solution showed the high Jc values of about 2.0 MA/cm2 after firing at the low heating rate of 2 °C/min in the crystallization step. However, the Jc value was degraded to the 0.7 MA/cm2 in the film fired at the heating rate of 70 °C/min in crystallization step. Additionally, in the case of the advanced
Fig. 3. Jc values of the films derived from the F-advanced solution with different heating rates from 2 °C/min to 70 °C/min in the crystallization step.
solution, the films were not uniformly coated on the substrate at the traveling rate of 10 m/h in the coating and calcination step, which resulted in low Ic values after firing for crystallization. As the next step, we have tried to develop new process conditions which could realize high superconducting properties with high speed both in coating/calcination and in crystallization steps. Fig. 2 shows the relationship between Jc values in the films from the F-advanced solution and the maximum temperature in the calcination step (T Cmax ) at the traveling rate of 10 m/h in coating and calcination after firing at the heating rate of 70 °C/min. As a result, the Jc values of the films with T Cmax of 500 °C were over 1.6 MA/cm2 at the high heating rate of 70 °C/min in the crystallization step. The high T Cmax made the calcined film better conditions than the low
Table 1 The growth conditions and the superconducting properties of the films from both the advanced and the F-advanced solutions. Starting solution
Viscosity of solution (cp)
Advanced
27
2.0
15
5.0
10
10.0
33 20 15
2.0 5.0 10.0
F-advanced
Traveling rate for coating/calcination (m/h)
Heating rate for crystallization (°C/min)
Jc (MA/cm2) @77 K
Thickness per coating (lm)
Total films thickness (lm)
2 70 2 70 2
1.7 1.7 1.6 1.25 0
0.19
1.33
0.193
1.36
2 2 2 70
2.0 2.0 2.0 0.7
0.195 0.199 0.24
0.98 0.99 1.02
H. Ichikawa et al. / Physica C 469 (2009) 1329–1331
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rate in the crystallization step played a role to cover the lack of the calcination process resulting in obtaining the high Jc values. Consequently, it is important to optimize the heating time, the heating rate and the maximum temperature in the calcination step for high Ic values. It indicates there is a room remained for further improvement of the Jc values and the higher production rate. 4. Conclusions
Heating rate: 2/min °C/min Under Oxygen atmosphere
Fig. 4. Temperature dependence of the weight loss for two different calcined films under the oxygen atmosphere by using TG–DTA.
T Cmax to maintain the heating rate, namely, production rate, in the crystallization step. Fig. 3 shows the Jc values of the films derived from the F-advanced solution with different heating rates from 2 °C/min to 70 °C/min in the crystallization step. The precursor films calcined by the heating profiles with different temperatures (T Cmax ) of 420 °C and 500 °C were used in this experiments. The films with the T Cmax of 420 °C, revealed the high Jc value of about 2.0 MA/cm2 under limited conditions only at the low heating rate of 2 °C/min in the crystallization step. The precursor films calcined by the T Cmax of 500 °C, however, showed Jc values of about 1.6 MA/cm2 as thick as 1.5 lm in the entire range of the heating rates from 2 °C/ min to 70 °C/min in the crystallization step. It could be explained that the properties were degraded at the high speed heating rate in the crystallization step due to the residue of fluoride, carbide and organic compounds in the calcined films. Fig. 4 shows the temperature dependence of the weight loss for two different calcined films under the oxygen atmosphere by using the Thermogravimetry/Differential Thermal Analysis (TG–DTA). The measurements were performed on two different powders from the precursor films which were calcined at different temperatures, (T Cmax ) of 420 °C and 500 °C. The samples were heated under the oxygen atmosphere at the heating rate of 2 °C/min to 550 °C with intermediate holdings at different temperatures of 400 °C, 450 °C and 500 °C for an hour. The calcined precursor films with T Cmax of 420 °C showed the same weight loss behavior as that with T Cmax of 500 °C during heating below 400 °C. However, the weight loss of the film with T Cmax of 420 °C was about 2.1 times more than that with T Cmax of 500 °C in the temperature above 400 °C. It was supposed that the results was due to the difference in the amounts of the residue including fluoride, carbide and organic compounds in the calcination films between the films with different T Cmax of 420 °C and 500 °C. It could be also explained that the slow heating
The F-advanced starting solution was prepared by dissolving Ffree salt of Y, TFA salt of Ba and Cu-Octylate with a cationic ratio of Y:Ba:Cu = 1:1.5:3 into the organic solvent in order to obtain coated conductors with high superconducting properties and a high production rate. The Jc value of 2.0 MA/cm2 was realized in the film with the high speed traveling rate in coating and calcination of 10 m/h by using an MT-RTR calcination furnace and the heating rate in crystallization of 2 °C/min using a fixed fired condition. However, the Jc values degraded in the films fired at a high heating rate in the crystallization step. Subsequently, we changed the maximum heating temperature in the calcination step to decompose the organics from the precursors. It was found that the increment of the maximum temperature in calcination step could increase the critical heating rate in the crystallization step for a higher production rate with high superconducting properties. As a result, the high Jc values of 1.6 MA/cm2 were confirmed in the films heat-treated by a high heating rate of 70 °C/min in crystallization. These superconducting properties are needed with the high speed production rate at our existing crystallization furnace. We found that modification of the calcination conditions was important for further improvement of the superconducting properties. Acknowledgements This work was supported by the New Energy and Industrial Technology Development Organization (NEDO) as the project of Collaborative Research and Development of Fundamental Technologies for Superconductivity Applications, and the project of Development of Materials & Power applications of Coated Conductors, (M-PACC). References [1] K. Nakaoka, J. Matsuda, M. Yoshizumi, T. Goto, Y. Yamada, T. Izumi, Y. Shiohara, IEEE Trans. Supercond. 17 (2007) 3313. [2] H. Fuji, T. Honjo, Y. Nakamura, T. Izumi, Y. Shiohara, R. Teranishi, M. Yoshimura, Y. Iijima, T. Saitoh, Physica C 378–381 (2002) 1013. [3] Y. Tokunaga, H. Fuji, R. Teranishi, J.S. Matsuda, S. Asada, T. Honjo, Y. Shiohara, Y. Iijima, T. Saitoh, Physica C 392–396 (2003) 909. [4] K. Nakaoka, J. Matsuda, Y. Kitoh, T. Goto, Y. Yamada, T. Izumi, Y. Shiohara, Physica C 463–465 (2007) 519. [5] T. Nakanishi, M. Yoshizumi, J. Matsuda, K. Nakaoka, Y. Kitoh, Y. Sutoh, T. Izumi, Y. Yamada, Y. Shiohara, Physica C 463–465 (2007) 515. [6] Y. Tokunaga, T. Honjo, T. Izumi, Y. Shiohara, Y. Iijima, T. Saitoh, T. Goto, A. Yoshinaka, A. Yajima, Cryogenics 44 (2004) 817.
Contents lists available at ScienceDirect
Physica C journal homepage: www.elsevier.com/locate/physc
High speed production of YBCO precursor films by advanced TFA-MOD process H. Ichikawa *, K. Nakaoka, M. Miura, Y. Sutoh, T. Nakanishi, A. Nakai, M. Yoshizumi, T. Izumi, Y. Shiohara Superconductivity Research Laboratory, ISTEC, 1-10-13, Shinonome, Koto-Ku, Tokyo 135-0062, Japan
a r t i c l e
i n f o
Article history: Available online 28 May 2009 PACS: 74.78. w 74.72.Bk 74.25.Sv Keywords: YBCO TFA-MOD Calcination
a b s t r a c t YBa2Cu3O7 y (YBCO) long tapes derived from the metal-organic deposition (MOD) method using the starting solution containing trifluoroacetate (TFA) have been developed with high critical currents (Ic) over 200 A/cm-width. However, high speed production of YBCO films is simultaneously necessary to satisfy the requirements of electric power device applications in terms of cost and the amounts of the tapes. In this work, we developed a new TFA-MOD starting solution using F-free salt of Y, TFA salt of Ba and Cu-Octylate for application to the coating/calcination process and discussed several issues by using the Multi-turn (MT) Reel-to-Reel (RTR) system calcination furnace for the purpose of high throughput without degradation of the properties. The coating system was improved for uniform deposition qualities in both longitudinal and transversal directions. YBCO films using the new starting solution at the traveling rate of 10 m/h in coating/calcination by the MT-RTR calcination furnace showed the values of the critical current density of 1.6 MA/cm2 as thick as 1.5 lm at 77 K under the self fields after firing at the high heating rate in the crystallization. Ó 2009 Elsevier B.V. All rights reserved.
1. Introduction YBa2Cu3O7 y (YBCO) coated conductors (CCs) with high critical current density (Jc) under the self-fields as well as the external magnetic field would be expected for application to some electric power devices such as power cables, Superconducting Magnetic Energy Storage (SMES) and transformers. The metal-organic deposition (MOD) method using the starting solution containing trifluoroacetate (TFA) salts of yttrium, barium and copper [2] is one of the most promising methods for fabrication of long-length YBCO tapes [1,3]. A 56 m long-tape of YBCO derived from the TFA-MOD process were developed to have the Ic value of 250 A/ cm-width using a conventional starting solution including TFA salt of Y, TFA salt of Ba, naphthenic acid of Cu with the Ba-deficient composition (Y:Ba:Cu = 1:1.5:3) [4–6]. However, there were two serious problems to be solved including the evolution of tar and different qualities in the different batch solutions since the naphthenic acid is extracted from the natural petroleum source. So, we developed a new starting solution including TFA salt of Y, TFA salt of Ba, Cu-Octylate with the Ba-deficient composition (Y:Ba:Cu = 1:1.5:3) which is called as ‘‘the advanced solution”. Although the advanced solution solved the above-mentioned problems, there is still an issue for higher speed production without degradation of properties for realizing low cost. In order to improve production speed, another starting solution was developed based on the similar concept to the advanced solution i.e. * Corresponding author. Tel.: +81 3 3536 5711; fax: +81 3 3536 8311. E-mail address: [email protected] (H. Ichikawa). 0921-4534/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.physc.2009.05.023
reduction of the fluorine content in the solution, which is called as the further advanced starting solution (F-advanced). The films derived from the F-advanced solution revealed the high Jc values of over 2.5 MA/cm2 in the short substrates. In this study, we investigated the influences of the maximum temperature and the heating rate in the calcination heat treatment step in order to apply the F-advanced solution to the MT-RTR calcination furnace for high production. We evaluated the properties of precursor films fired at high heating rate in the crystallization step. 2. Experimental The starting solutions were prepared by dissolving F-free of Y for the F-advanced solution or TFA salt of Y for the advanced one, TFA salt of Ba and Cu-Octylate with a cationic ratio of Y:Ba:Cu = 1:1.5:3 into the organic solvent. The stating solution was coated on the CeO2 buffered IBAD-Gd2Zr2O7/Hastelloy substrates by the dip coating method followed by heating up to 420–510 °C in an O2 gas flow using the Multi-turn (MT) Reel-toReel (RTR) system calcination furnace which has a typical temperature gradient of 25 °C/min. The film thickness per single coating was controlled by viscosity of the solution. Finally these samples were heated to 740–800 °C in the mixed humid (P(H2O) = 15 vol.) gas flow of argon and oxygen P(O2) = 10–102 Pa. The final thickness of the YBCO superconductor films was about 1.0–1.6 lm. The precursor films and the crystallized YBCO films were examined by Xray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). In addition, the chemical
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Fig. 1. Properties of the YBCO films derived from the advanced solution and the Fadvanced one at different traveling rates in the coating and calcination step.
Fig. 2. Relationship between the Jc values in the films from the F-advanced solution and the maximum temperature of calcinations (T Cmax ) at the traveling rate of 10 m/h in coating and calcination after firing at the heating rate of 70 °C/min.
composition analysis of these films and the film thickness were measured by Inductively Coupled Plasma (ICP). The critical current (Ic) of the crystallized films was measured at 77 K under the selffields by the DC four-probe method with the criterion of voltage of 1 lV/cm. 3. Results and discussion Fig. 1 shows the property of the YBCO films derived from the advanced solution and the F-advanced one at the traveling rate of coating and calcination, 2 m/h, 5 m/h and 10 m/h, respectively. The films from the F-advanced starting solution maintained the high Jc values up to the high speed traveling rate of 10 m/h in the coating and calcination step, while the films from the advanced one revealed degradation of Jc values with increasing the traveling rate. The degradation of Jc values was thought to be due to the incomplete precursor films because of the high heating rate and deficiency in calcination times. We found that the F-advanced solution was appropriate to fabricate superconducting films with high Jc values at the high traveling rate of 10 m/h in the coating and calcination step and at the low heating rate of 2 °C/min in the crystallization step. Table 1 shows the growth conditions and the superconducting properties of the films from both the advanced and the F-advanced solutions. It was found that there are large difference in the heating rates of 2 and 70 °C/min in the crystallization step for the Jc values especially in the films coated and calcined at the high traveling rate. The precursor films coated and calcined at the traveling rate of 10 m/h using the F-advanced solution showed the high Jc values of about 2.0 MA/cm2 after firing at the low heating rate of 2 °C/min in the crystallization step. However, the Jc value was degraded to the 0.7 MA/cm2 in the film fired at the heating rate of 70 °C/min in crystallization step. Additionally, in the case of the advanced
Fig. 3. Jc values of the films derived from the F-advanced solution with different heating rates from 2 °C/min to 70 °C/min in the crystallization step.
solution, the films were not uniformly coated on the substrate at the traveling rate of 10 m/h in the coating and calcination step, which resulted in low Ic values after firing for crystallization. As the next step, we have tried to develop new process conditions which could realize high superconducting properties with high speed both in coating/calcination and in crystallization steps. Fig. 2 shows the relationship between Jc values in the films from the F-advanced solution and the maximum temperature in the calcination step (T Cmax ) at the traveling rate of 10 m/h in coating and calcination after firing at the heating rate of 70 °C/min. As a result, the Jc values of the films with T Cmax of 500 °C were over 1.6 MA/cm2 at the high heating rate of 70 °C/min in the crystallization step. The high T Cmax made the calcined film better conditions than the low
Table 1 The growth conditions and the superconducting properties of the films from both the advanced and the F-advanced solutions. Starting solution
Viscosity of solution (cp)
Advanced
27
2.0
15
5.0
10
10.0
33 20 15
2.0 5.0 10.0
F-advanced
Traveling rate for coating/calcination (m/h)
Heating rate for crystallization (°C/min)
Jc (MA/cm2) @77 K
Thickness per coating (lm)
Total films thickness (lm)
2 70 2 70 2
1.7 1.7 1.6 1.25 0
0.19
1.33
0.193
1.36
2 2 2 70
2.0 2.0 2.0 0.7
0.195 0.199 0.24
0.98 0.99 1.02
H. Ichikawa et al. / Physica C 469 (2009) 1329–1331
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rate in the crystallization step played a role to cover the lack of the calcination process resulting in obtaining the high Jc values. Consequently, it is important to optimize the heating time, the heating rate and the maximum temperature in the calcination step for high Ic values. It indicates there is a room remained for further improvement of the Jc values and the higher production rate. 4. Conclusions
Heating rate: 2/min °C/min Under Oxygen atmosphere
Fig. 4. Temperature dependence of the weight loss for two different calcined films under the oxygen atmosphere by using TG–DTA.
T Cmax to maintain the heating rate, namely, production rate, in the crystallization step. Fig. 3 shows the Jc values of the films derived from the F-advanced solution with different heating rates from 2 °C/min to 70 °C/min in the crystallization step. The precursor films calcined by the heating profiles with different temperatures (T Cmax ) of 420 °C and 500 °C were used in this experiments. The films with the T Cmax of 420 °C, revealed the high Jc value of about 2.0 MA/cm2 under limited conditions only at the low heating rate of 2 °C/min in the crystallization step. The precursor films calcined by the T Cmax of 500 °C, however, showed Jc values of about 1.6 MA/cm2 as thick as 1.5 lm in the entire range of the heating rates from 2 °C/ min to 70 °C/min in the crystallization step. It could be explained that the properties were degraded at the high speed heating rate in the crystallization step due to the residue of fluoride, carbide and organic compounds in the calcined films. Fig. 4 shows the temperature dependence of the weight loss for two different calcined films under the oxygen atmosphere by using the Thermogravimetry/Differential Thermal Analysis (TG–DTA). The measurements were performed on two different powders from the precursor films which were calcined at different temperatures, (T Cmax ) of 420 °C and 500 °C. The samples were heated under the oxygen atmosphere at the heating rate of 2 °C/min to 550 °C with intermediate holdings at different temperatures of 400 °C, 450 °C and 500 °C for an hour. The calcined precursor films with T Cmax of 420 °C showed the same weight loss behavior as that with T Cmax of 500 °C during heating below 400 °C. However, the weight loss of the film with T Cmax of 420 °C was about 2.1 times more than that with T Cmax of 500 °C in the temperature above 400 °C. It was supposed that the results was due to the difference in the amounts of the residue including fluoride, carbide and organic compounds in the calcination films between the films with different T Cmax of 420 °C and 500 °C. It could be also explained that the slow heating
The F-advanced starting solution was prepared by dissolving Ffree salt of Y, TFA salt of Ba and Cu-Octylate with a cationic ratio of Y:Ba:Cu = 1:1.5:3 into the organic solvent in order to obtain coated conductors with high superconducting properties and a high production rate. The Jc value of 2.0 MA/cm2 was realized in the film with the high speed traveling rate in coating and calcination of 10 m/h by using an MT-RTR calcination furnace and the heating rate in crystallization of 2 °C/min using a fixed fired condition. However, the Jc values degraded in the films fired at a high heating rate in the crystallization step. Subsequently, we changed the maximum heating temperature in the calcination step to decompose the organics from the precursors. It was found that the increment of the maximum temperature in calcination step could increase the critical heating rate in the crystallization step for a higher production rate with high superconducting properties. As a result, the high Jc values of 1.6 MA/cm2 were confirmed in the films heat-treated by a high heating rate of 70 °C/min in crystallization. These superconducting properties are needed with the high speed production rate at our existing crystallization furnace. We found that modification of the calcination conditions was important for further improvement of the superconducting properties. Acknowledgements This work was supported by the New Energy and Industrial Technology Development Organization (NEDO) as the project of Collaborative Research and Development of Fundamental Technologies for Superconductivity Applications, and the project of Development of Materials & Power applications of Coated Conductors, (M-PACC). References [1] K. Nakaoka, J. Matsuda, M. Yoshizumi, T. Goto, Y. Yamada, T. Izumi, Y. Shiohara, IEEE Trans. Supercond. 17 (2007) 3313. [2] H. Fuji, T. Honjo, Y. Nakamura, T. Izumi, Y. Shiohara, R. Teranishi, M. Yoshimura, Y. Iijima, T. Saitoh, Physica C 378–381 (2002) 1013. [3] Y. Tokunaga, H. Fuji, R. Teranishi, J.S. Matsuda, S. Asada, T. Honjo, Y. Shiohara, Y. Iijima, T. Saitoh, Physica C 392–396 (2003) 909. [4] K. Nakaoka, J. Matsuda, Y. Kitoh, T. Goto, Y. Yamada, T. Izumi, Y. Shiohara, Physica C 463–465 (2007) 519. [5] T. Nakanishi, M. Yoshizumi, J. Matsuda, K. Nakaoka, Y. Kitoh, Y. Sutoh, T. Izumi, Y. Yamada, Y. Shiohara, Physica C 463–465 (2007) 515. [6] Y. Tokunaga, T. Honjo, T. Izumi, Y. Shiohara, Y. Iijima, T. Saitoh, T. Goto, A. Yoshinaka, A. Yajima, Cryogenics 44 (2004) 817.