Single crystal growth, transport and scanning tunneling microscopy and spectroscopy of FeSe1-xSx
| Autor: | E. Lechner, Mahmoud Abdel-Hafiez, Olga S. Volkova, Andrey M. Kovalskii, Alexander N. Vasiliev, Larisa Shvanskaya, Daniel J. Trainer, Maria Iavarone, Yevgeniy Ovchenkov, Dmitriy A. Chareev |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Scanning tunneling spectroscopy Analytical chemistry Fermi surface 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences law.invention chemistry.chemical_compound chemistry law Liquid crystal Selenide 0103 physical sciences General Materials Science Crystallization Scanning tunneling microscope 010306 general physics 0210 nano-technology Spectroscopy Phase diagram |
| Zdroj: | Crystengcomm CrystEngComm |
| Popis: | Single crystals of sulfur-substituted iron selenide, FeSe1-xSx, were grown within eutectics of molten halides, AlCl3/KCl, AlCl3/KCl/NaCl or AlCl3/KBr, under permanent temperature gradient. The innovative "ampoule in ampoule" design of a crystallization vessel allows obtaining mm-sized plate-like single crystals with a sulfur content up to x ∼ 0.19. The sharp anomalies in the physical properties indicate the superconducting and nematic phase transitions in FeSe0.96 at TC = 8.4 K and TN = 90 K, respectively. Scanning tunneling microscopy reveals the presence of dumbbell defects associated with Fe vacancies and dark defects at the chalcogen site associated with S within the FeSe1-xSx series of compounds. Scanning tunneling spectroscopy shows the presence of two different superconducting gaps at both hole and electron pockets of the Fermi surface for low S content levels. As a function of sulfur content, TC follows the conventional dome-shaped curve while TN decreases with x. The overall appearance of the T-x phase diagram of FeSe1-xSx suggests the importance of nematic fluctuations for the formation of the superconducting state in these compounds. © 2018 The Royal Society of Chemistry. |
| Databáze: | OpenAIRE |
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