Development of a ferromagnetic component in the superconducting state of Fe-excess Fe1.12Te1-xSex by electronic charge redistribution

作者：Li Wen Hsien^*; Karna Sunil K; Hsu Han; Li Chi Yen; Lee Chi Hung; Sankar Raman; Chou Fang Cheng

来源：Scientific Reports, 2015, 5(1): 10951.

DOI：10.1038/srep10951

The general picture established so far for the links between superconductivity and magnetic ordering in iron chalcogenide Fe1+y(Te1-xSex) is that the substitution of Se for Te directly drives the system from the antiferromagnetic end into the superconducting regime. Here, we report on the observation of a ferromagnetic component that developed together with the superconducting transition in Fe-excess Fe1.12Te1-xSex crystals using neutron and x-ray diffractions, resistivity, magnetic susceptibility and magnetization measurements. The superconducting transition is accompanied by a negative thermal expansion of the crystalline unit cell and an electronic charge redistribution, where a small portion of the electronic charge flows from around the Fe sites toward the Te/Se sites. First-principles calculations show consistent results, revealing that the excess Fe ions play a more significant role in affecting the magnetic property in the superconducting state than in the normal state and the occurrence of an electronic charge redistribution through the superconducting transition.

• 出版日期2015-6-16
• 单位中央民族大学