Evolution of Superconductivity and Antiferromagnetic Order in Ba (Fe0.92-xCo0.08Vx)2 As2

Single crystals of the laminar Fe-based superconductor Ba(Fe_0.92-xCo_0.08V_x)₂As₂ were grown by the self-flux method for investigation on the interplay between superconductivity and antiferromagnetic correlations. The superconducting state emerges at a critical V concentration where the lattice structural transition with an associated spin-glass state reaches a maximum transition temperature (see the Figure). The result from the transport, magnetization and neutron diffraction experiments suggects a Griffiths quantum critical point with a lattice twist at the onset of the unconventional superconductivity in the BaFe₂As₂ system.

This is the first completed scientific output of our newly constructed cold neutron triple-axis spectrometer at China Advanced Research Reactor outside Beijing, as a National Major Research Instrumentation Project.

Read more at Physical Review B:
http://doi.org/10.1103/PhysRevB.101.174516