High magnetic field studies of the vortex lattice structure in YBa 2 Cu 3 O 7
High magnetic field studies of the vortex lattice structure in YBa 2 Cu 3 O 7
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YBa 2 Cu 3 O 7 涡旋晶格结构的强磁场研究
DOI：
10.1103/physrevb.90.054502
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发表时间：
2014
影响因子：
3.7
通讯作者：
Cameron A
中科院分区：
文献类型：
--
作者：
Cameron A
本文报道了用小角中子散射（SANS）方法测量无孪晶超导体中涡旋晶格（VL）的结果，将以前研究的<11T的最大磁场扩展到16.7T，并在平行轴方向上施加磁场，这是对该超导相区域涡旋物质的微观研究。我们发现，高磁场VL显示出一个菱形结构，与场相关的协调，通过一个正方形的配置没有锁定到一个场无关的结构。VL钉扎随温度的升高而降低，但可以看出，即使在晶格结构的不可逆温度以上，VL相关长度也会受到影响。在高场和温度下，我们观察到VL熔化转变，这似乎是一阶的。过渡区上方的涡旋液相不产生可检测的SANS信号。
We report on small-angle neutron scattering (SANS) measurements of the vortex lattice (VL) in twin-free, extending the previously investigated maximum magnetic field of <11 T up to 16.7 T with the field applied parallel to thecaxis. This is a microscopic study of vortex matter in this region of the superconducting phase. We find that the high magnetic field VL displays a rhombic structure, with a field-dependent coordination that passesthrougha square configuration with no lock-in to a field-independent structure. The VL pinning reduces with increasing temperature but is seen to affect the VL correlation length even above the irreversibility temperature of the lattice structure. At high field and temperature we observe a VL melting transition, which appears to be first order. The vortex liquid phase above the transition does not give a detectable SANS signal.