Evidence of δl pinning induced by citric acid doping in MgB2 superconductor

摘要 本文研究了柠檬酸掺杂的MgB2超导材料的Jc-B行为及其钉扎机理.在纯MgB2多晶样品中，δTc钉扎起主要作用，而在掺杂的样品中，则是δl钉扎和δTc钉扎共同作用，并且δl钉扎机理占主要作用，其贡献比重随着掺杂量的增加而增加.从Jc-B行为和钉扎行为的分析都可以得到 关键词: 柠檬酸 / MgB2 / δTc钉扎 / δl钉扎 Abstract The critical current density (Jc) and flux-pinning mechanism of MgB2 doped with citric acid (C6H8O7) from 0 to 30wt% have been investigated in detail by magnetic and resistive measurements. The temperature dependence of critical current density，Jc(T)，at particular field within the single vortex regime was analyzed. δTc pinning mechanism was found to be the only important pinning mechanism in pure MgB2 samples，while δl pinning is dominant with little effect of δTc pinning for citric acid doped samples. It was observed that the contribution of δl pinning enhances with the increasing doping level of critic acid，and it was also found that MgB2 doped with 15wt% critic acid shows the best performance in Jc-B behavior. Keywords: citric acid / MgB2 / δTc pinning / δl pinning 作者及机构信息 孙辉辉3, 杨烨3, 王磊3, Cheng C. H.1, 冯勇2, 赵勇4 (1)School of Materials，University of New South Wales，Sydney 2052，NSW Australia; (2)西北有色金属研究院，西部超导科技公司，西安 710016; (3)西南交通大学材料先进技术教育部重点实验室，超导研究开发中心，成都 610031; (4)西南交通大学材料先进技术教育部重点实验室，超导研究开发中心，成都 610031；School of Materials，University of New South Wales，Sydney 2052，NSW Australia 基金项目: 国家自然科学基金（批准号： 50588201，50672078，50872116），高等学校博士学科点专项科研基金（批准号：200806130023），国家重点基础研究发展计划（973）项目（批准号：2007CB616906），澳大利亚研究委员会基金（批准号：DP0559872，DP0881739），西南交通大学生博士创新基金，西南交通大学科技发展基金，西南交通大学科技创新基金资助的课题. Authors and contacts Sun Hui-Hui3, Yang Ye3, Wang Lei3, Cheng C. H.1, Feng Yong2, Zhao Yong4 (1)School of Materials，University of New South Wales，Sydney 2052，NSW Australia; (2)西北有色金属研究院，西部超导科技公司，西安 710016; (3)西南交通大学材料先进技术教育部重点实验室，超导研究开发中心，成都 610031; (4)西南交通大学材料先进技术教育部重点实验室，超导研究开发中心，成都 610031；School of Materials，University of New South Wales，Sydney 2052，NSW Australia 参考文献 [1] ［1］Nagamatsu J，Nakagawa N，Muranaka T，Zenitani Y，Akimitsu J 2001 Nature 410 63 [2] ［2］Tan M Q，Tao X M 2001 Acta Phys. Sin. 50 1193 (in Chinese) ［谭明秋、陶向明 2001 物理学报 50 1193］ [3] ［3］Yang D S，Wu B M，Li B，Zheng W H，Li S Y，Chen X H，Cao L Z 2003 Acta Phys. Sin. 52 2015 (in Chinese) ［杨东升、吴柏枚、李波、郑卫华、李世燕、陈仙辉、曹烈兆 2003 物理学报 52 2015］ [4] ［4］Yang H S，Yu M，Li S Y，Li P C，Chai Y S，Zhang L，Chen X H，Cao L Z 2001 Acta Phys. Sin. 50 1197 (in Chinese) ［杨宏顺、余旻、李世燕、李鹏程、柴一晟、章良、陈先辉、曹烈兆 2001 物理学报 50 1197］ [5] ［5］Shang X F，Tao X M，Chen W B，Chen H X，Wang M，Tan M Q 2008 Acta Phys. Sin. 57 5838 (in Chinese) ［尚学府、陶向明、陈文斌、陈会贤、王淼、谭明秋 2008 物理学报 57 5838］ [6] ［6］Shi L B，Ren J Y，Zhang F Y，Zhang G H，Yu Z Q 2007 Acta Phys. Sin. 56 5353 (in Chinese) ［史力斌、任骏原、张凤云、张国华、余增强 2007 物理学报 56 5353］ [7] ［7］Feng W J，Xia T D，Liu T Z，Zhao W J，Wei Z Q 2005 Chin. Phys. 14 2325 [8] ［8］Chen R H，Zhu M Y，Li Y，Li W X，Jin H M，Dou S X 2006 Acta Phys. Sin. 55 4878 (in Chinese) ［陈荣华、朱明原、李瑛、李文献、金红明、窦士学 2006 物理学报 55 4878］ [9] ［9］Zhang X P，Ma Y W，Gao Z S，Yu Z G，K.Watanabe，Wen H H 2006 Acta Phys. Sin. 55 4873 (in Chinese) ［张现平、马衍伟、高召顺、禹争光、K.Watanabe、闻海虎 2006 物理学报 55 4873］ [10] ］Dou S X，Soltanian S，Horvat J，Wang X L，Zhou S H，Lonescu M，Liu H K 2002 Appl. Phys. Lett. 81 3419 [11] ］Zhou S H，Pan A V，Qin M J，Liu H K，Dou S X 2003 Physica C 387 321 [12] ］Yamamoto A，Shimoyama J，Ueda S，Iwayama I，Horii S，Kishio K2005 Supercond. Sci. Technol. 18 1323 [13] ］Cheng C H，Yang Y，Munroe P，Zhao Y 2007 Supercond. Sci. Technol. 20 296 [14] ］Qin M J，Wang X L，Liu H K，Dou S X 2002 Phys. Rev. B 65 132508 [15] ］Wang X L，Zeng R，Kim J H，Liu L，Dou S X 2008 Phys. Rev. B 77 174501 [16] ］Ghorbani S R，Wang X L，Dou S X，Lee S，Hossain M S A 2008 Phys. Rev. B 78 184502 [17] ］Kang W N，Kim H J，Choi E M，Lee S L 2002 Phys. Rev. B 65 64512 [18] ］Takenobu T，Ito T，Chi D H，Prassides K，Iwasa Y 2001 Phys. Rev. B 64 134513 [19] ］Avdeev M，Jorgensen J D，Ribeiro R A，Bud’ko S L，Canfield P C 2003 Physica C 387 301 [20] ］Wang X L，Yao Q W，Horvat J，Qin M J，Dou S X 2004 Supercond. Sci. Technol. 17 L21 [21] ］Wilke R H T，Budko S L，Canfield P C，Finnemore D K 2004 Phys. Rev. Lett. 92 217003 [22] ］Blatter G，Feigelman M V，Geshkenbein V B，Larkin A I，Vinokur V M 1994 Rev. Mod. Phys. 66 1125 [23] ］Wen H H，Schnack H G，Griessen R，Dam B，Rector J 1995 Physica C 241 353 [24] ］Yeoh W K，Dou S X 2007 Physica C 456 170 [25] ］Zeng R，Lu L，Wang J L，Horvat J，Li W X，Shi D Q，Dou S X，Tomsic M，Rindfleisch M 2007 Supercond. Sci. Technol. 20 L43 [26] ］Kazakov S M，Puzniak R，Rogacki K，Mironov A V，Zhigadlo N D，Jun J，Soltmann C，Batlogg B，Karpinski J 2005 Phys. Rev. B 71 024533 [27] ］Rowell J M 2003 Supercond. Sci. Technol. 16 R17 [28] ］Mickelson W，Cumings J，Han W Q，Zettl A 2002 Phys. Rev. B 65 052505 施引文献