TY - JOUR
T1 - Demonstration of excellent Jc Performance in (AE,Na)Fe2As2 (AE
T2 - Sr, Ba) PIT Wires
AU - Tamegai, Tsuyoshi
AU - Suwa, Takahiro
AU - Miyawaki, Daisuke
AU - Pyon, Sunseng
AU - Takano, Katsutoshi
AU - Kajitani, Hideki
AU - Koizumi, Norikiyo
AU - Awaji, Satoshi
N1 - Funding Information:
Manuscript received October 30, 2018; accepted February 17, 2019. Date of publication March 14, 2019; date of current version April 12, 2019. This work was supported in part by a bilateral joint research project between Japan and China, and in part by JSPS KAKENHI Grant 17H01141. (Corresponding author: Tsuyoshi Tamegai.) T. Tamegai, T. Suwa, D. Miyawaki, and S. Pyon are with the Univer-sty of Tokyo, Tokyo 113-8656, Japan (e-mail:, tamegai@ap.t.u-tokyo.ac.jp; ind_m_22555_kanto@yahoo.co.jp; miyadai883@gmail.com; pyon@ap.t.u-tokyo.ac.jp).
Publisher Copyright:
© 2002-2011 IEEE.
PY - 2019/8
Y1 - 2019/8
N2 - Na-substituted 122-type iron-based superconductors were synthesized and fabricated into superconducting tapes and wires. Good Jc performance of Ag-sheathed Sr0.45Na0.55Fe2As2 pressed tapes was demonstrated, and it was further improved by using AgSn as a sheath material. The improved Jc characteristics are due to the reduction of the optimum sintering temperature by ∼100 °C, which suppressed the reaction between the sheath and the core. However, the fabrication of good Sr0.45Na0.55Fe2As2 round wire using the hot isostatic press method failed, due possibly to the segregation of Na in the core. To avoid the segregation of Na, we fabricated round wires employing (Ba,Na)Fe2As2 rather than underdoped (Sr,Na)Fe2As2. Jc in Ba0.6Na0.4Fe2As2 round wire processed 700 °C under the pressure of 175 MPa reached 1.5 × 105 and 2.0 × 104 A/cm2 at self-field and 100 kOe, respectively. These values are more than fifty percent of the largest Jc in (Ba,K)Fe2As2 round wires, demonstrating the excellent performance of (Ba,Na)Fe2As2 wires.
AB - Na-substituted 122-type iron-based superconductors were synthesized and fabricated into superconducting tapes and wires. Good Jc performance of Ag-sheathed Sr0.45Na0.55Fe2As2 pressed tapes was demonstrated, and it was further improved by using AgSn as a sheath material. The improved Jc characteristics are due to the reduction of the optimum sintering temperature by ∼100 °C, which suppressed the reaction between the sheath and the core. However, the fabrication of good Sr0.45Na0.55Fe2As2 round wire using the hot isostatic press method failed, due possibly to the segregation of Na in the core. To avoid the segregation of Na, we fabricated round wires employing (Ba,Na)Fe2As2 rather than underdoped (Sr,Na)Fe2As2. Jc in Ba0.6Na0.4Fe2As2 round wire processed 700 °C under the pressure of 175 MPa reached 1.5 × 105 and 2.0 × 104 A/cm2 at self-field and 100 kOe, respectively. These values are more than fifty percent of the largest Jc in (Ba,K)Fe2As2 round wires, demonstrating the excellent performance of (Ba,Na)Fe2As2 wires.
KW - Critical current density
KW - high-temperature superconductors
KW - superconducting filaments and wires
KW - type II superconductors
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U2 - 10.1109/TASC.2019.2905159
DO - 10.1109/TASC.2019.2905159
M3 - Article
AN - SCOPUS:85064720514
SN - 1051-8223
VL - 29
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
IS - 5
M1 - 8667380
ER -