Publications (29)
Trapping a magnetic field of 14.8 T using stacked coated conductors of 12 mm width
Masahiro Suyama, Sunseng Pyon, Yasuhiro Iijima +2
We fabricated a compact (131212.5 mm) trapped-field magnet by stacking 200 pieces of EuBaCuO coated conductors with BaHfO nanorods as…
Asymmetric stress engineering of dense dislocations in brittle superconductors for strong vortex pinning
Meng Han, Chiheng Dong, Chao Yao +17
Large lossless currents in high-temperature superconductors (HTS) critically rely on dense defects with suitable size and dimensionality to pin vortices, with dislocations being pa…
High transport current superconductivity in powder-in-tube Ba0.6K0.4Fe2As2 tapes at 27 tesla
He Huang, Chao Yao, Chiheng Dong +6
The high upper critical field and low anisotropy of iron-based superconductors make them being particularly attractive for high-field applications. However, the current carrying ca…
Realization of practical level current densities in Sr0.6K0.4Fe2As2 tape conductors for high-field applications
Xianping Zhang, Chao Yao, He Lin +10
122 type pnictide superconductors are of particular interest for high-field applications because of their large upper critical fields Hc2 (> 100 T), low Hc2 anisotropy r (< 2), and…
Enhancement of critical current density in (Ba,Na)Fe2As2 round wires using high-pressure sintering
Sunseng Pyon, Daisuke Miyawaki, Tsuyoshi Tamegai +4
We fabricated (Ba,Na)Fe2As2 superconducting wires using the powder-in-tube method and hot isostatic pressing. By improving powder synthesis processes compared with previous studies…
Strongly enhanced current densities in Sr0.6K0.4Fe2As2 superconducting tapes
He Lin, Chao Yao, Xianping Zhang +6
Improving transport current has been the primary issue for practical application of superconducting wires and tapes. However, the porous nature of powder-in-tube (PIT) processed ir…
Tensile Strain Dependence of Critical Current for RHQ-Nb3Al Wires
Xinzhe Jin, Hidetoshi Oguro, Tatsushi Nakamoto +6
KEK and NIMS have been jointly developing Nb3Al superconducting wire with a rapid heating and quenching (RHQ) method towards high field accelerator magnets in the Large Hadron Coll…
Critical current density and microstructure of iron sheathed multifilamentary Sr1-xKxFe2As2/Ag composite conductors
Chao Yao, He Lin, Qianjun Zhang +6
Iron-based superconductors have been considered to be very promising in high-field applications, for which multifilamentary wire and tape conductors with high mechanical strength a…
High critical current density in textured Ba-122/Ag tapes fabricated by scalable rolling process
Chiheng Dong, Chao Yao, He Lin +7
The industrial manufacturing of the long-length iron-pnictide wires and tapes requires simple and low-cost technology. Although the transport critical current density of the FeAs-1…
Improved transport critical currents in Ag and Pb co-doped BaxK1-xFe2As2 superconducting tapes
Chao Yao, Chunlei Wang, Xianping Zhang +8
Fe-clad BaxK1-xFe2As2 superconducting tapes were fabricated by the ex situ powder-in-tube method combined with a short high-temperature annealing technique. The effect of annealing…
Thermodynamic approach for enhancing superconducting critical current performance
Masashi Miura, Go Tsuchiya, Takumu Harada +14
The addition of artificial pinning centers has led to an impressive increase in critical current density () in a superconductor, enabling record-breaking all-superconduc…
High-performance Ba1-xKxFe2As2 superconducting tapes with grain texture engineered via a scalable and cost-effective fabrication
Shifa Liu, Chao Yao, He Huang +6
Nowadays the development of high-field magnets strongly relies on the performance of superconducting materials. Iron-based superconductors exhibit high upper critical fields and lo…
Large transport critical currents of powder-in-tube Sr0.6K0.4Fe2As2/Ag superconducting wires and tapes
Lei Wang, Yanpeng Qi, Dongliang Wang +7
We report significant transport critical currents firstly achieved in Sr0.6K0.4Fe2As2 wires and tapes with a Tc = 34 K, which were fabricated through an in-situ powder-in-tube proc…
Strengthened proximity effect at grain boundaries to enhance inter-grain supercurrent in Ba1-xKxFe2As2 superconductors
Zhe Cheng, Chiheng Dong, Huan Yang +5
Iron-based superconductors have great potential for high-power applications due to their prominent high-field properties. One of the central issues in enhancing the critical curren…
Longitudinal Magnetoresistance in YBaCuO at High Magnetic Fields of up to 100 T
Shiyue Peng, Xu-Guang Zhou, Yasuhiro H. Matsuda +7
The investigation of transport characteristics in high-temperature superconductors under magnetic fields is one of the most important topics in condensed matter physics and transpo…
Single Crystal Growth and Transport Properties of van der Waals Materials Te ( = Ti, Zr, Hf)
Yuto Hasuo, Takahiro Urata, Masaaki Araidai +3
Monolayers of Te (/ = Ti, Zr, Hf) were theoretically predicted to be two-dimensional topological insulators, but little has been known about the physical properties o…
Fabrication and Transport Properties of 100 m Class Sr0.6K0.4Fe2As2 Wires and Pancake Coils
Xianping Zhang, Hidetoshi Oguro, Chao Yao +6
Iron-pnictides are hotly studied since 2008 in the superconducting materials research area, due to their special properties and unclear mechanism. Big achievement has been made in…
Enhancement of transport critical current density of SmFeAsO1-xFx tapes fabricated by an ex-situ powder-in-tube method with a Sn-presintering process
Qianjun Zhang, Chao Yao, He Lin +10
SmFeAsO1-xFx (Sm1111) tapes were prepared by an ex-situ powder-in-tube method with a Sn-presintering process. Scanning electron microscopy revealed apparent difference in microstru…
Ordering phenomena of spin trimers accompanied by large geometrical Hall effect
Shang Gao, Max Hirschberger, Oksana Zaharko +10
The wavefuntion of conduction electrons moving in the background of a non-coplanar spin structure can gain a quantal phase - Berry phase - as if the electrons were moving in a stro…
Enhancement of critical current densities in (Ba,K)Fe2As2 wires and tapes using HIP technique
Sunseng Pyon, Takahiro Suwa, Akiyoshi Park +6
(Ba,K)Fe2As2 superconducting wires and tapes are fabricated by using hot isostatic pressing (HIP) technique, and their superconducting properties are studied. In the HIP round wire…
Effect of starting materials on the superconducting properties of SmFeAsO1-xFx tapes
Chunlei Wang, Chao Yao, Xianping Zhang +7
SmFeAsO1-xFx tapes were prepared using three kinds of starting materials. It shows that the starting materials have an obvious effect on the impurity phases in final superconductin…
Quadrupolar Susceptibility and Magnetic Phase Diagram of PrNiCd with Non-Kramers Doublet Ground State
Tatsuya Yanagisawa, Hiroyuki Hidaka, Hiroshi Amitsuka +8
In this study, ultrasonic measurements were performed on a single crystal of cubic PrNiCd, down to a temperature of 0.02 K, to investigate the crystalline electric field…
High-field Magnetic Torque Measurements in (CH)CHNHCuCl
Takehiro Saito, Takahiko Sasaki, Takao Suzuki +5
High-field magnetic torque measurements were carried out in the spin gap system (CH)CHNHCuCl. It was observed that the magnitude of the magnetic torque is almo…
R&D works for Superconducting Magnet for Future Accelerator Applications in Japan
Toru Ogitsu, Tatsushi Nakamoto, Ken-ichi Sasaki +6
KEK cryogenics science center is developing superconducting magnet technology for future accelerator science. Three major technological categories are focused; 1) high precision 3D…
Doping Dependence of Upper Critical Field of High-Tc Cuprate Bi2+xSr2-xCaCu2O8+d Estimated from Irreversibility Field at Zero Temperature
Junichiro Kato, Shigeyuki Ishida, Tatsunori Okada +12
We investigated the temperature (T) dependence of the irreversibility field Hirr(T) in high-critical-temperature cuprate Bi2+xSr2-xCa1-yYyCu2O8+d (Bi-2212) single crystals over a w…
Fabrication of small superconducting coils using (Ba,A)Fe2As2 (A: Na, K) round wires with large critical current densities
Sunseng Pyon, Haruto Mori, Tsuyoshi Tamegai +6
We report the fabrication of small (Ba,A)Fe2As2 (A: Na, K) coils using 10 m-class long round wires, fabricated by powder-in-tube (PIT) method. Coils are sintered using hot-isostati…
Vortex pinning and dynamics in high performance Sr0.6K0.4Fe2As2 superconductor
Chiheng Dong, He Lin, He Huang +7
We have studied vortex pinning and dynamics in a Sr0.6K0.4Fe2As2 superconducting tape with critical current density Jc~0.1 MA/cm2 at 4.2 K and 10 T. It is found that grain boundary…
High critical current density and low anisotropy in textured Sr1-xKxFe2As2 tapes for high field applications
Zhaoshun Gao, Yanwei Ma, Chao Yao +5
From the application point of view, large critical current densities Jc (H) for superconducting wires are required, preferably for magnetic fields higher than 5 T. Here we show tha…
Hot pressing to enhance the transport Jc of Sr0.6K0.4Fe2As2 superconducting tapes
He Lin, Chao Yao, Xianping Zhang +9
High-performance Sr0.6K0.4Fe2As2 (Sr-122) tapes have been successfully fabricated using hot pressing (HP) process. The effect of HP temperatures (850-925 C) on the c-axis texture,…