Abstract
The vanadium doping effects on the superconductivity and magnetism of iron pnictides are investigated in by transport, susceptibility, and neutron scattering measurements. The doping of magnetic impurity V causes a fast suppression of superconductivity with reduced at a rate of approximately 7.4 K/1% V. On the other hand, for , long-range -type antiferromagnetic order is recovered upon V doping, in contrast to the sample with no detectable magnetic order. The value of ordered magnetic moments of follows a domelike evolution versus doping concentration . A possible Griffiths-type antiferromagnetic region of multiple coexisting phases in the phase diagram of is identified, in accordance with previous theoretical predictions based on the cooperative behavior of magnetic impurities and conduction electrons mediating the Ruderman-Kittel-Kasuya-Yosida interactions between them.
- Received 28 January 2020
- Revised 12 April 2020
- Accepted 30 April 2020
DOI:https://doi.org/10.1103/PhysRevB.101.174516
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