期刊
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
卷 24, 期 9, 页码 -出版社
MDPI
DOI: 10.3390/ijms24097896
关键词
vortex glass; Lindemann melting; anisotropic superconductors; pnictides; vortex melting line; multi-harmonic susceptibility
Understanding the vortex matter and dynamics is crucial for practical applications of superconductors. We have investigated the vortex glass-vortex liquid phase transitions in CaKFe4As4 and BaFe2(As0.68P0.32)(2) single crystals using multi-harmonic susceptibility studies. Our findings suggest that the phase transition can be treated as a melting process according to Lindemann's approach, even in iron-based superconductors. The experimental data are consistent with a temperature-dependent London penetration depth given by a 3D XY fluctuations model.
For practical applications of superconductors, understanding the vortex matter and dynamics is of paramount importance. An important issue in this context is the transition of the vortex glass, which is a true superconducting phase, into a vortex liquid phase having a linear dissipation. By using multi-harmonic susceptibility studies, we have investigated the vortex glass-vortex liquid phase transitions in CaKFe4As4 and BaFe2(As0.68P0.32)(2) single crystals. The principle of our method relates the on-set of the third-harmonic susceptibility response with the appearance of a vortex-glass phase in which the dissipation is non-linear. Similar to the high-critical temperature cuprate superconductors, we have shown that even in these iron-based superconductors with significant lower critical temperatures, such phase transition can be treated as a melting in the sense of Lindemann's approach, considering an anisotropic Ginzburg-Landau model. The experimental data are consistent with a temperature-dependent London penetration depth given by a 3D XY fluctuations model. The fitting parameters allowed us to extrapolate the vortex melting lines down to the temperature of liquid hydrogen, and such extrapolation showed that CaKFe4As4 is a very promising superconducting material for high field applications in liquid hydrogen, with a melting field at 20 K of the order of 100 T.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据