Microstructure and structural phase transitions in iron-based superconductors

• Published in: Chinese physics B 2013-08, Vol.22 (8), p.123-134
• Main Author: 王臻 蔡瑶 杨槐馨 田焕芳 王秩伟 马超 陈震 李建奇
• Format: Article
• Language: English
• Subjects: Crystal structure; Distortion; Inhomogeneities; Microstructure; Phase transformations; Physical properties; Superconductivity; Superconductors; Transformations; 不均匀性; 微观结构特征; 晶体结构; 组织; 结构相变; 超导材料; 铁基; 高温超导体
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/22/8/087409

Crystal structures and microstructural features, such as structural phase transitions, defect structures, and chemical and structural inhomogeneities, are known to have profound effects on the physical properties of superconducting materials. Recently, many studies on the structural properties of Fe-based high-Tc superconductors have been published. This review article will mainly focus on the typical microstructural features in samples that have been well characterized by physical measurements. （i） Certain common structural features are discussed, in particular, the crystal structural features for different superconducting families, the local structural distortions in the Fe2Pn2 （Pn = P, As, Sb） or FeeCh2 （Ch = S, Se, Te） blocks, and the structural transformations in the 122 system. （ii） In FeTe（Se） （11 family）, the superconductivity, chemical and structural inhomogeneities are investigated and discussed in correlation with superconductivity. （iii） In the Ko.sFe1.6＋xSe2 system, we focus on the typical compounds with emphasis on the Fe-vacancy order and phase separations. The microstructural features in other superconducting materials are also briefly discussed.