| Autor: |
Keng-Yu Yeh, Tung-Sheng Lo, Wu, Phillip M., Kuei-Shu Chang-Liao, Ming-Jye Wang, Maw-Kuen Wu |
| Předmět: |
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| Zdroj: |
Proceedings of the National Academy of Sciences of the United States of America; 6/9/2020, Vol. 117 Issue 23, p12606-12610, 5p |
| Abstrakt: |
We studied the electrical transport of Fe4+δSe5 single-crystal nanowires exhibiting √5 x √5 Fe-vacancy order and mixed valence of Fe. Fe4+δSe5 compound has been identified as the parent phase of FeSe superconductor. A first-order metal-insulator (MI) transition of transition temperature TMI ~28 K is observed at zero magnetic fields (B). Colossal positive magnetoresistance emerges, resulting from the magnetic field-dependent MI transition. TMI demonstrates anisotropic magnetic field dependence with the preferred orientation along the c axis. At temperature T < ~17 K, the state of near-magnetic field-independent resistance, which is due to spin polarized even at zero fields, preserves under magnetic fields up to B = 9 T. The Arrhenius law shift of the transition on the source-drain frequency dependence reveals that it is a nonoxide compound with the Verwey-like electronic correlation. The observation of the magnetic field-independent magnetoresistance at low temperature suggests it is in a charge-ordered state below T ~17 K. The results of the field orientation measurements indicate that the spin-orbital coupling is crucial in √5 x √5 Fe vacancy-ordered Fe4+δSe5 at low temperatures. Our findings provide valuable information to better understand the orbital nature and the interplay between the MI transition and superconductivity in FeSe-based materials. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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