MgB4와 Mg 분말을 원료로 사용하여 고상반응법으로 제조한 MgB2 초전도체의 상생성과 초전도 특성
Superconducting Properties and Phase Formation of MgB2 Superconductors Prepared by the Solid State Reaction Method using MgB4 and Mg Powder
0
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
MgB2 bulk superconductors are synthesized by the solid state reaction of (MgB4+xMg) precursors with excessive Mg compositions (x=1.0, 1.4, 2.0 and 2.4). The MgB4 precursors are synthesized using (Mg+B) powders. The secondary phases (MgB4 and MgO) present in the synthesized MgB4 are removed by HNO3 leaching. It is found that the formation reaction of MgB2 is accelerated when Mg excessive compositions are used. The magnetization curves of Mg1+xB2 samples show that the transition from the normal state to the superconducting state of the Mg excessive samples with x=0.5 and x=0.7 are sharper than that of MgB2. The highest Jc-B curve at 5 K and 20 K is achieved for x=0.5. Further addition of Mg decreases the Jc owing to the formation of more pores in the MgB2 matrix and smaller volume fraction of MgB2.
Abstract
MgB2 bulk superconductors are synthesized by the solid state reaction of (MgB4+xMg) precursors with excessive Mg compositions (x=1.0, 1.4, 2.0 and 2.4). The MgB4 precursors are synthesized using (Mg+B) powders. The secondary phases (MgB4 and MgO) present in the synthesized MgB4 are removed by HNO3 leaching. It is found that the formation reaction of MgB2 is accelerated when Mg excessive compositions are used. The magnetization curves of Mg1+xB2 samples show that the transition from the normal state to the superconducting state of the Mg excessive samples with x=0.5 and x=0.7 are sharper than that of MgB2. The highest Jc-B curve at 5 K and 20 K is achieved for x=0.5. Further addition of Mg decreases the Jc owing to the formation of more pores in the MgB2 matrix and smaller volume fraction of MgB2.
참고문헌 (22)
- J. Nagamatsu, , Nature, 410, pp.63~ (2001)
- V. Ferrando, , Appl. Phys. Lett., 87, pp.252509~ (2005)
- D. K. Finnemore, , Phys. Rev. Lett., 86, pp.2420~ (2001)
- C. Buzea, , Supercond. Sci. Technol., 14, pp.115~ (2001)
- W. Goldacker, , Supercond. Sci. Technol., 17, pp.363~ (2004)
- A. Yamamoto, , Supercond. Sci. Technol, 18, pp.116~ (2005)
- X. Xu, , J. Appl. Phys., 103, pp.023912~ (2008)
- A. Berenov, , Supercond. Sci. Technol., 17, pp.1093~ (2004)
- J. D. Moore, , Supercond. Sci. Technol., 20, pp.278~ (2007)
- Y. Zhao, , Appl. Phys. Lett., 79, pp.1154~ (2001)
- Y. Sun, , Supercond. Sci. Technol., 20, pp.261~ (2007)
- B. H. Jun, , Supercond. Sci. Technol., 21, pp.105006~ (2008)
- K. S. Tan, , Supercond. Sci. Technol., 21, pp.105013~ (2008)
- J. H. Yi, , Physica C, 469, pp.1192~ (2009)
- C. -J. Kim, , Physica C, 502, pp.4~ (2014)
- K. L. Tan, , Phys. Status Solidi A, 210(3), pp.616~ (2013)
- Kai Sin Tan, "Superconducting Properties of a MgB2 Bulk Formed by Using a MgB4 + Mg Mixture", Journal of the Korean Physical Society, 54(4), pp.1626~1629 (2009), 한국물리학회
- D. Nardelli, , Supercond. Sci. Technol., 26, pp.075010~ (2013)
- A. Ito, , IEEE Trans. Appl. Supercond., 23, pp.7101005~ (2013)
- K. L. Tan, , Solid State Sci. Technol., 19, pp.15~ (2011)
- C. P. Bean, , Rev. Mod. Phys., 36, pp.31~ (1964)
- S. T. Kim, , J. Alloys Compd., 470, pp.85~ (2009)