27th International Conference on Low Temperature Physics | |
Emergence of superconductivity and magnetic ordering tuned by Fe-vacancy in alkali-metal Fe chalcogenides RbxFe2-ySe2 | |
Kobayashi, Yoshiaki^1 ; Kototani, Shouhei^1 ; Itoh, Masayuki^1 ; Sato, Masatoshi^2 | |
Nagoya University, Furo-cho, Chikusa-ku, Nagoya | |
464-8602, Japan^1 | |
Research Center for Neutron Science and Technology, Comprehensive Research Organization for Science and Society (CROSS), 162-1 Shirakata, Tokai | |
319-1106, Japan^2 | |
关键词: Antiferromagnetic transition; Magnetically actives; NMR measurements; NMR spectrum; Ordered phase; Paramagnetic phase; Three phasis; Vacancy concentration; | |
Others : https://iopscience.iop.org/article/10.1088/1742-6596/568/2/022024/pdf DOI : 10.1088/1742-6596/568/2/022024 |
|
来源: IOP | |
【 摘 要 】
Samples of RbxFe2-ySe2exhibiting superconductivity [superconducting (SC) samples] undergo a phase-separation into two phases, a Fe-vacancy ordered phase with antiferromagnetic (AFM) transition at TN1∼500 K (AFM1 phase) and a phase with little Fe- vacancy and SC transition at Tc∼30 K (SC phase). The samples of RbxFe2-ySe2exhibiting no SC behaviour (non-SC samples) are phase-separated into three phases, The AFM1 phase, another AFM phase with TN2∼150 K (AFM2 phase), and a paramagnetic phase with no SC transitions (paramagnetic non-SC phase). In this paper, we present The experimental results of magnetic susceptibility, electrical resistivity, and NMR measurements on single crystals of RbxFe2-ySe2to reveal physical properties of these co-existing phases in The SC and non-SC samples. The87Rb and77Se NMR spectra show that The Fe vacancy concentration is very small in The Fe planes of The SC phase, whereas The AFM2 and paramagnetic non-SC phases in non-SC samples have larger amount of Fe vacancies. The randomness induced by The Fe vacancy in The non-SC samples makes The AFM2 and paramagnetic non-SC phases insulating/semiconducting and magnetically active, resulting in The absence of The superconductivity in RbxFe2-ySe2.
【 预 览 】
Files | Size | Format | View |
---|---|---|---|
Emergence of superconductivity and magnetic ordering tuned by Fe-vacancy in alkali-metal Fe chalcogenides RbxFe2-ySe2 | 1303KB | download |