Nov 18, 2015
Doping-enhanced antiferromagnetism in Ca1-xLaxFeAs2
Physical Review B - Condensed Matter and Materials Physics
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- Volume
- 92
- Number
- 18
- Language
- English
- Publishing type
- Research paper (scientific journal)
- DOI
- 10.1103/PhysRevB.92.180508
- Publisher
- American Physical Society
In iron pnictides, high temperature superconductivity emerges after suppressing antiferromagnetism by doping. Here, we show that antiferromagnetism in Ca1-xLaxFeAs2 is robust against and even enhanced by doping. Using As75-nuclear magnetic resonance and nuclear quadrupole resonance techniques, we find that an antiferromagnetic order occurs below the Néel temperature TN=62 K at a high doping concentration (x=0.15) where superconductivity sets in at the transition temperature Tc=35 K. In the superconducting state coexisting with antiferromagnetism, the nuclear-spin-lattice relaxation rate 1/T1 becomes proportional to T, indicating gapless excitations. Unexpectedly, TN is enhanced with increasing doping, rising up to TN=70 K at x=0.24. The obtained phase diagram of this system enriches the physics of iron-based high-Tc superconductors.
- Link information
- ID information
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- DOI : 10.1103/PhysRevB.92.180508
- ISSN : 1550-235X
- ISSN : 1098-0121
- SCOPUS ID : 84948691159