Study of high pressure electronic state on iron-oxynictide high-T_C superconductors using as probe for thermoelectric effect

热电效应探针铁氮氧化物高温超导体高压电子态研究

• 批准号: 21740260
• 负责人: HEDO Masato
• 金额: $ 2.75万
• 依托单位: University of the Ryukyus
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2009
• 资助国家: 日本
• 起止时间: 2009 至 2010
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21740260/
• 关键词: 高圧力; ゼーベック効果; 鉄ヒ素系超伝導体; 電子状態; 鉄ヒ素超伝導体

Seebeck coefficient (S/T) of Eu_<0.5>Ca_<0.5>Fe_2As_2 showed sign inversion before appearance of superconducting state (SC) and it was found that state of Fermi surface was notably transmuted just before expression of SC. In the case of EuFe_2As_2 verifying precursor phenomenon of SC, the S/T may change positive with further increasing pressure after negative to zero of S/T and it is expected to present similar behavior of Eu_<0.5>Ca_<0.5>Fe_2As_2. For EuFe_2As_2 and Eu_<0.5>Ca_<0.5>Fe_2As_2, T_2-dependence coefficient A of resistivity was prominently decrease after emergence of SC, it is able to understand that the density of state around Fermi level is distinct decrease above critical pressure P_C in this system.

EU_ <0.5> Ca__ <0.5> Fe_2as_2的Seebeck系数（S/T）在出现超导状态（SC）之前显示出符号反转，发现Fermi表面的状态在SC表达之前就显然是在传播的。在EUFE_2AS_2验证SC的前体现象的情况下，S/T可能会随着S/T负零后的压力进一步增加而变化，并且预计它将呈现EU_ <0.5> Ca__ <0.5> Fe_2as_2的相似行为。对于EUFE_2AS_2和EU_ <0.5> CA_______2AS_2，T_2依赖性系数A的电阻率A在SC出现后显着降低，它能够理解，FERMI级别周围的状态密度在该系统中的关键压力P_C以上是P_C的差异。

项目成果

Possible Existence of Magnetic Polaron in Nearly Ferromagnetic Semiconductor β-US_2

近铁磁半导体β-US_2中可能存在磁极化子

• 发表时间: 2009
• 期刊: Journal of Physical Society of Japan 78
• 作者: S.Ikeda;et al.,
• 通讯作者: et al.,