Microstructural analysis of phase separation in iron chalcogenide superconductors
Microstructural analysis of phase separation in iron chalcogenide superconductors
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DOI：
10.1088/0953-2048/25/8/084023
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发表时间：
2012-08-01
影响因子：
3.6
通讯作者：
Grovenor, C. R. M.
中科院分区：
文献类型：
--
作者：
Speller, S. C.;Britton, T. B.;Grovenor, C. R. M.
铁基超导体中超导性、磁性和晶体结构之间的相互作用是凝聚态物理学界非常感兴趣的话题，因为它被认为是理解高温超导机制的关键。碱金属掺杂的铁硫属化合物超导体具有其他铁基超导材料所没有的几个独特特征，例如室温下的反铁磁有序性、有序铁空位的存在和高电阻率正常态特性。详细的微观结构分析是必不可少的，以了解这些不寻常的属性的起源。在这里，我们已经使用了一系列的互补扫描电子显微镜为基础的技术，包括高分辨率电子背散射衍射映射，以高精度和亚微米的空间分辨率来评估局部变化的组成和晶格参数。在CsxFe 2-ySe 2晶体中观察到相分离，次要相以板状形态分布在整个晶体中。我们的结果是一致的超导性只发生在少数相。
The interplay between superconductivity, magnetism and crystal structure in iron-based superconductors is a topic of great interest amongst the condensed matter physics community as it is thought to be the key to understanding the mechanisms responsible for high temperature superconductivity. Alkali metal doped iron chalcogenide superconductors exhibit several unique characteristics which are not found in other iron-based superconducting materials such as antiferromagnetic ordering at room temperature, the presence of ordered iron vacancies and high resistivity normal state properties. Detailed microstructural analysis is essential in order to understand the origin of these unusual properties. Here we have used a range of complementary scanning electron microscope based techniques, including high-resolution electron backscatter diffraction mapping, to assess local variations in composition and lattice parameter with high precision and sub-micron spatial resolution. Phase separation is observed in the CsxFe2-ySe2 crystals, with the minor phase distributed in a plate-like morphology throughout the crystal. Our results are consistent with superconductivity occurring only in the minority phase.