在周围环境和高压下,Fe(1+delta) Se0.57Te0.43中的结构相变和超导性
Nathalie C Gresty1, Yasuhiro Takabayashi, Alexey Y Ganin
1Department of Chemistry, Durham University, Durham DH1 3LE, UK.
Journal of the American Chemical Society
|October 30, 2009
概括
压力显著增强了铁化物中的超导性,临界温度 (T) 达到23.3K.在3GPa时,结构转向单晶对称与最大T相对应,揭示了晶体和电子特性之间的联系.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
背景情况:
- 基于Fe的超导体是最近发现的一类材料,具有独特的特性.
- 三级铁素化物,如Fe{1.03) Se{0.57) Te{0.43),在环境压力下表现出超导性.
- 了解结构和超导性之间的相互作用对于设计新材料至关重要.
研究的目的:
- 为了研究压力下Fe{1.03) Se{0.57) Te{0.43) 的结构性和电子性质之间的关系.
- 要确定施加的压力如何影响超导的临界温度 (T (c)).
- 探索由压力引起的结构相变.
主要方法:
- 使用高分辨率同步龙X射线衍射分析结构变化.
- 超导的临界温度 (T(c)) 被测量为施加压力的函数.
- 晶体结构和对称性在各种压力点的特征.
主要成果:
- 超导的临界温度 (T) 随着压力增加,在大约3GPa时达到23.3K的最大值.
- 一个结构的转变从orthorhombic到单临床对称发生在3GPa左右.
- 在更高的压力 (12 GPa) 下,该材料变为金属,但失去了其超导特性.
结论:
- 晶体结构和铁原超导体的电子特性之间存在密切的联系.
- 压力诱导的结构对称性变化直接影响超导体的行为.
- 这些发现为这些材料的超导机制提供了洞察力.
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