title: Microscopic Coexistence of Superconductivity and Antiferromagnetism in Underdoped Ba(Fe(1-x)Ru(x))2As2.
abstract: We use (75)As nuclear magnetic resonance to investigate the local electronic properties of Ba(Fe(1-x)Ru(x))(2)As(2) (x = 0.23). We find two phase transitions: to antiferromagnetism at T(N) ≈ 60 K and to superconductivity at T(C) ≈ 15 K. Below T(N), our data show that the system is fully magnetic, with a commensurate antiferromagnetic structure and a moment of 0.4μ(B)/Fe. The spin-lattice relaxation rate 1/(75)T(1) is large in the magnetic state, indicating a high density of itinerant electrons induced by Ru doping. On cooling below T(C), 1/(75)T(1) on the magnetic sites falls sharply, providing unambiguous evidence for the microscopic coexistence of antiferromagnetism and superconductivity.
authors.affiliation: Department of Physics, Renmin University of China, Beijing 100872, China.
authors.forename: Long
authors.initials: L
authors.lastname: Ma
authors.forename: G F
authors.initials: GF
authors.lastname: Ji
authors.forename: Jia
authors.initials: J
authors.lastname: Dai
authors.forename: X R
authors.initials: XR
authors.lastname: Lu
authors.forename: M J
authors.initials: MJ
authors.lastname: Eom
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.forename: B
authors.initials: B
authors.lastname: Normand
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Yu