10.1021/ic400727g.s001
Jinggeng Zhao
Jinggeng
Zhao
Haozhe Liu
Haozhe
Liu
Lars Ehm
Lars
Ehm
Dawei Dong
Dawei
Dong
Zhiqiang Chen
Zhiqiang
Chen
Qingqing Liu
Qingqing
Liu
Wanzheng Hu
Wanzheng
Hu
Nanlin Wang
Nanlin
Wang
Changqing Jin
Changqing
Jin
Pressure-Induced
Phase Transitions and Correlation between Structure and Superconductivity
in Iron-Based Superconductor Ce(O<sub>0.84</sub>F<sub>0.16</sub>)FeAs
American Chemical Society
2013
13.9 GPa
charge reservoir layer
33.8 GPa
transition region
54.9 GPa
bond distances
structure evolution
pressure dependences
structure analysis
superconducting transition temperature Tc
lanthanide cations
superconductivity changes
Ce
room temperature
isostructural phase transition
19.9 GPa
2013-07-15 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Pressure_Induced_Phase_Transitions_and_Correlation_between_Structure_and_Superconductivity_in_Iron_Based_Superconductor_Ce_O_sub_0_84_sub_F_sub_0_16_sub_FeAs/2396314
High-pressure angle-dispersive X-ray
diffraction experiments on iron-based superconductor Ce(O<sub>0.84</sub>F<sub>0.16</sub>)FeAs were performed up to 54.9 GPa at room temperature.
A tetragonal to tetragonal isostructural phase transition starts at
about 13.9 GPa, and a new high-pressure phase has been found above
33.8 GPa. At pressures above 19.9 GPa, Ce(O<sub>0.84</sub>F<sub>0.16</sub>)FeAs completely transforms to a high-pressure tetragonal phase,
which remains in the same tetragonal structure with a larger <i>a</i>-axis and smaller <i>c</i>-axis than those of
the low-pressure tetragonal phase. The structure analysis shows a
discontinuity in the pressure dependences of the Fe–As and
Ce–(O, F) bond distances, as well as the As–Fe–As
and Ce–(O, F)–Ce bond angles in the transition region,
which correlates with the change in <i>T</i><sub>c</sub> of this compound upon compression. The isostructural phase transition
in Ce(O<sub>0.84</sub>F<sub>0.16</sub>)FeAs leads to a drastic drop
in the superconducting transition temperature <i>T</i><sub>c</sub> and restricts the superconductivity at low temperature. For
the 1111-type iron-based superconductors, the structure evolution
and following superconductivity changes under compression are related
to the radius of lanthanide cations in the charge reservoir layer.