The pseudogap behavior in the stoichiometric FeSe superconductor (Tc~9.4 K)
| Autor: | Song, Yoo Jang, Hong, Jong Beom, Min, Byeong Hun, Lee, Kyu Jun, Jung, Myung Hwa, Rhyee, Jong-Soo, Kwon, Yong Seung |
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| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | Journal of the Korean Physical Society Vol. 59, No. 2, 2011, pp.312-316 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.3938/jkps.59.312 |
| Popis: | This paper reports the synthesis and superconducting behaviors of the tetragonal iron-chalcogenide superconductor FeSe. The electrical resistivity and magnetic moment measurements confirmed its superconductivity with a $T_c^{zero}$ and $T_c^{mag}$ at 9.4 K under ambient pressure. EPMA indicated the sample to have a stoichiometric Fe:Se ratio of 1:1 ($\pm$0.02). The Seebeck coefficient which was 12.3 $\mu$V/K at room temperature, changed to a negative value near 200 K, indicating it to be a two carriers material. Above $T_c$, the $\rho(T)$ curve revealed an 'S' shape. Hence $d\rho(T)/dT$, and $d^2\rho(T)/dT^2$ showed pseudogap-like behavior at $T^*$=110 K according to the resistivity curvature mapping (RCM) method for high $T_c$ cuprates. Moreover, the magnetoresistance $\rho_H(T)/\rho_{H=0}$ under a magnetic field and the Seebeck coefficient $S(T)$ revealed revealed pseudogap-like behavior near $T^*$. Interestingly, at the same temperature, 30 K, the sign of $S(T)$ and all signs of $d^2\rho(T)/dT^2$ changed from negative to positive above $T_c$. Comment: 10 pages, 6 figures |
| Databáze: | arXiv |
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