Observation of two collapsed phases in CaRbFe4As4
| Autor: | Ryan L. Stillwell, Daniel J. Campbell, Yogesh K. Vohra, Johnpierre Paglione, Xiangfeng Wang, Jason R. Jeffries, Limin Wang, Samuel T. Weir |
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| Rok vydání: | 2019 |
| Předmět: |
Diffraction
Physics Superconductivity Condensed matter physics 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Tetragonal crystal system Electrical resistivity and conductivity Hall effect Lattice (order) 0103 physical sciences 010306 general physics 0210 nano-technology |
| Zdroj: | Physical Review B. 100 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | We report the observation of the pressure-induced, fully collapsed tetragonal phase of $\mathrm{CaRbF}{\mathrm{e}}_{4}\mathrm{A}{\mathrm{s}}_{4}$ for $P\ensuremath{\sim}22\phantom{\rule{0.16em}{0ex}}\mathrm{GPa}$ via high-pressure x-ray diffraction and magnetotransport measurements. The x-ray measurements, along with resistivity measurements, show that there is an initial half-collapsed tetragonal phase for $6lPl22\phantom{\rule{0.16em}{0ex}}\mathrm{GPa}$, in which superconductivity is continuously suppressed from ${T}_{\mathrm{c}}=35\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ at $P=3.1\phantom{\rule{0.16em}{0ex}}\mathrm{GPa}$ to ${T}_{\mathrm{c}}l2\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ for $P\ensuremath{\ge}17.2\phantom{\rule{0.16em}{0ex}}\mathrm{GPa}$, as well as signs of the fully collapsed tetragonal phase near $P=22\phantom{\rule{0.16em}{0ex}}\mathrm{GPa}$. Density functional calculations suggest that both of these transitions are driven by increased As-As bonding, first across the Ca layer, and then at the second transition, across the Rb layer. Although electrical resistivity measurements in the fully collapsed tetragonal phase do not show superconductivity, there is a change in the slope of both the Hall coefficient and the longitudinal resistance near 22 GPa, suggesting a strong correlation between the electronic and lattice degrees of freedom in this new iron-based superconductor. |
| Databáze: | OpenAIRE |
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