https://scholar.dgist.ac.kr/handle/20.500.11750/34 2026-04-05T04:36:42Z 2026-04-05T04:36:42Z Kwon, Yong Seung https://scholar.dgist.ac.kr/handle/20.500.11750/47130 2025-07-25T03:23:13Z 2017-10-02T15:00:00Z

Title: Optical properties in superconducting Ca1-xLax10Pt3As8Fe2As25 x0, 0.082 single crystals Author(s): Kwon, Yong Seung

2017-10-02T15:00:00Z Hajiri, Tetsuya Niwa, R. Ito, Takahiro Matsunami, Masaharu Min, Byeong Hun Kimura, Shojiro Kwon, Yong Seung https://scholar.dgist.ac.kr/handle/20.500.11750/16583 2025-07-25T02:35:30Z 2012-08-28T15:00:00Z

Title: Polarization-dependent three-dimensional angle-resolved photoemission study on LiFeAs Author(s): Hajiri, Tetsuya; Niwa, R.; Ito, Takahiro; Matsunami, Masaharu; Min, Byeong Hun; Kimura, Shojiro; Kwon, Yong Seung Abstract: We report the orbital character of the Fermi surfaces for the Fe-based superconductor LiFeAs using the polarization-dependent three-dimensional angle-resolved photoemission spectroscopy and the angular-dependent dipole selection rule analysis. The evaluated orbital character is well reproduced by the band calculation. The results demonstrate that the polarization-dependent ARPES combined with the selection rule analysis is useful to identify the orbital character of the Fe-based unconventional superconductivity. © Published under licence by IOP Publishing Ltd.

2012-08-28T15:00:00Z Ahmad, Dawood Min, Byeong Hun Lee, Jung Hee Kim, Gun Cheol Kim, Young Cheol Kwon, Yong Seung https://scholar.dgist.ac.kr/handle/20.500.11750/16582 2025-07-25T03:26:06Z 2013-09-14T15:00:00Z

Title: Analysis of peak effect in the critical current density and flux pinning properties in iron based superconducting Ca10(Pt4As 8)(Fe2-xPtxAs2)5 single crystal Author(s): Ahmad, Dawood; Min, Byeong Hun; Lee, Jung Hee; Kim, Gun Cheol; Kim, Young Cheol; Kwon, Yong Seung Abstract: We present the magnetic properties of the iron based superconducting Ca10(Pt4As8)(Fe2-xPt xAs2)5 (x =0.01) single crystal as a function of field and time. The single crystals were grown by Bridgman method and showed Tc of 32 K. The results show that the well-known secondary peak effect becomes prominent in certain temperature range in the field dependent magnetic hysteresis. Moreover, the maximum of pinning force density F max versus Hmax follows a scaling law Fp,max 49.5Hmax3/2 indicating the single type pinning mechanism is involved in the sample within our measured temperature range. The time dependence of the magnetization indicates thermally activated flux motion and the relaxation rate reveals a plateau in the temperature region where secondary peak effect is more prominent after that a sudden increase is observed. We found that the magnetization dependence of activation energy U obtained by Maley's method follows a power law in low temperature region with exponent μ 0.15 which is in good agreement with collective pinning theory. © Published under licence by IOP Publishing Ltd.

2013-09-14T15:00:00Z