標題: | Possibility of vortex lattice structural phase transition in the superconducting pnictide Ba(Fe0.925Co0.075)(2)As-2 |
作者: | Kopeliansky, R. Shaulov, A. Shapiro, B. Ya. Yeshurun, Y. Rosenstein, B. Tu, J. J. Li, L. J. Cao, G. H. Xu, Z. A. 電子物理學系 Department of Electrophysics |
公開日期: | 1-三月-2010 |
摘要: | We present magnetic measurements in a single crystal of the newly discovered superconducting ironpnictide Ba(Fe0.925Co0.075)(2)As-2. The magnetization loops exhibit a second magnetization peak (SMP) similar to that observed in most high-temperature superconductors (HTSs). Magnetic relaxation measurements reveal a minimum in the normalized relaxation rate, S = d ln M/d ln t, located in between the SMP onset and the peak fields. The SMP in HTSs is commonly associated with the vortex order-disorder phase transition. However, in Ba(Fe0.925Co0.075)(2)As-2 the onset and peak fields, as well as the minimum point in S, exhibit strong temperature dependence down to low temperatures, excluding the possibility for such a transition. We suggest that the SMP in Ba(Fe0.925Co0.075)(2)As-2 is associated with a vortex structural phase transition from rhombic to square lattice taking place at field and temperatures corresponding to the minimum point of S. A theoretical fit to the transition line, based on a recent theoretical model for vortex structural phase transition, shows good agreement with the experimental results. |
URI: | http://dx.doi.org/10.1103/PhysRevB.81.092504 http://hdl.handle.net/11536/149917 |
ISSN: | 1098-0121 |
DOI: | 10.1103/PhysRevB.81.092504 |
期刊: | PHYSICAL REVIEW B |
Volume: | 81 |
Issue: | 9 |
起始頁: | 0 |
結束頁: | 0 |
顯示於類別: | 期刊論文 |