DISORDER-DRIVEN INTERMEDIATE STATE IN THE LATTICE MELTING TRANSITION OF BI2SR2CACU2O8+DELTA SINGLE CRYSTALS
DISORDER-DRIVEN INTERMEDIATE STATE IN THE LATTICE MELTING TRANSITION OF BI2SR2CACU2O8+DELTA SINGLE CRYSTALS
复制标题
BI2SR2CACU2O8 Delta 单晶晶格熔化转变中无序驱动的中间态
DOI：
10.1103/physrevb.56.r14295
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发表时间：
1997
影响因子：
3.7
通讯作者：
M. Henini
中科院分区：
文献类型：
--
作者：
A. Oral;J. Barnard;S. Bending;S. Ooi;H. Taoka;T. Tamegai;M. Henini
用霍尔扫描探针显微镜研究了Bi2Sr2CaCu2O8+δ高温超导体的高质量单晶。我们观察到明显的高通量密度条纹，这些条纹几乎一直持续到晶体的临界温度。我们发现，这些区域对涡旋晶格熔化转变施加了无序驱动的中间态，其结构由固、液条交替组成。我们认为，剥离可能反映了由于在晶体生长过程中原子平台边缘的扩散增强而形成的氧掺杂水平略有不同的区域。我们无法分辨出涡旋晶格熔线上方的条纹中的离散涡旋。我们推测，要么涡旋液体有效地屏蔽了任何存在的钉扎通量，要么吉布斯自由能的空间变化可能在这些温度下对涡旋液体施加了密度调制。
Scanning Hall probe microscopy has been used to study high quality single crystals of the Bi 2 Sr 2 CaCu 2 O 8+ δ high-temperature superconductor over a wide range of temperatures at low fields. We observe pronounced stripes of high flux density which persist well above the melting line almost up to the critical temperature of the crystal. We show that these regions impose a disorder-driven intermediate state on the vortex lattice melting transition with a structure composed of alternating solid and liquid strips. We propose that the striping may reflect regions of slightly different oxygen doping level formed due to enhanced diffusion at the edges of atomic terraces during crystal growth. We are unable to resolve discrete vortices in the stripes above the vortex lattice melting line. We speculate either that the vortex liquid efficiently screens any pinned flux present or that spatial variations in the Gibbs free energy may be imposing a density modulation on the vortex liquid at these temperatures.