Realization of Wide-range Measurement on Electric-field versus Current-density Characteristics from 10-5 V/m down to 10-11 V/m Based on Hall-probe Magnetic Microscopy
呉 澤宇, 岸川 創紀, 東川 甲平, 木須 隆暢 （九大）
Abstract:Electric-field (E) versus current-density (J) characteristic is an important property of superconducting materials from the viewpoint of both fundamental and practical point of view. To understand the vortex dynamics and dissipation mechanism under the influence of thermal fluctuation, the non-linear E-J characteristics need to be clarified experimentally and theoretically. To describe the properties under various applications in AC and DC operation mode, the range of corresponding E may change more than 8 orders of magnitude. Precise modeling of such non-linear E-J characteristics with wide-range of E should be established as a function of operation conditions such as magnetic field and temperature. Many previous works have presented with discrete and semi-quantitative results by combining transport (10-5 ~ 10-2 V/m) and magnetic measurements such as vibrating sample magnetometry (10-9 ~ 10-5 V/m), 3rd harmonics measurement (10-8 ~ 10-4 V/m) and SQUID magnetometer (< 10-7 V/m) [1, 2]. However, the previous methods could not yet fully cover the dynamic ranges of the electric field continuously. In this study, we demonstrated a systematic methodology by using Hall-probe magnetic microscopy in order to obtain E-J characteristics with the dynamic range of E from 10-5 V/m down to 10-11 V/m benefiting from high temporal resolution (higher than 0.1 s) of the Hall-probe magnetic microscopy and flux annealing method.
Acknowledgement: This work was supported by JSPS KAKENHI Grant Number JP19H05617.
Reference
[1] Ö. Polat et al, Phys. Rev. B 84, 024519 (2011).
[2] H. Yamasaki et al., IEEE Trans. Appl. Supercond., 15, pp. 3636-3639 (2005)