Uniaxial pressure effect on the magnetic ordered moment and transition temperatures in BaFe${}_{2-x}{T}_x$As${}_2$ ($T=$Co, Ni)

Abstract

We use neutron diffraction and muon spin relaxation to study the effect of in-plane uniaxial pressure on the antiferromagnetic (AF) orthorhombic phase in BaFe${}_2$As${}_2$ and its Co- and Ni-substituted members near optimal superconductivity. In the low temperature AF ordered state, uniaxial pressure necessary to detwin the orthorhombic crystals also increases the magnetic ordered moment, reaching an 11$\%$ increase under 40 MPa for BaFe${}_{1.9}$Co${}_{0.1}$As${}_2$, and a 15$\%$ increase for BaFe${}_{1.915}$Ni${}_{0.085}$As${}_2$. We also observe an increase of the AF ordering temperature ($T_N$) of about 0.25 K/MPa in all compounds, consistent with density functional theory calculations that reveal better Fermi surface nesting for itinerant electrons under uniaxial pressure. The doping dependence of the magnetic ordered moment is captured by combining dynamical mean field theory with density functional theory, suggesting that the pressure-induced moment increase near optimal superconductivity is closely related to quantum fluctuations and the nearby electronic nematic phase.

6 pages, 4 figures, 12 supplementary pages, 12 supplementary figures, PRB accepted as Rapid Communication

References in corpus (15)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Evidence for an electron nematic phase transition in underdoped iron pnictide superconductors
• Magnetic order in BaFe2As2, the parent compound of the FeAs based superconductors in a new structural family
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Theory of Electron Nematic Order in LaOFeAs
• Ising and Spin orders in Iron-based Superconductors
• The challenge of unravelling magnetic properties in LaFeAsO
• Nematic spin correlations in the tetragonal state of uniaxial strained BaFe2-xNixAs2
• Superconductivity coexisting with phase-separated static magnetic order in (Ba,K)Fe${}_2$As${}_2$, (Sr,Na)Fe${}_2$As${}_2$ and CaFe${}_2$As${}_2$
• Incommensurate spin-density wave order in electron-doped BaFe2As2 superconductors
• Coexistence and competition of the short-range incommensurate antiferromagnetic order with superconductivity in BaFe2-xNixAs2
• Muon spin relaxation studies of magnetic order and superfluid density in antiferromagnetic NdOFeAs, BaFe2As2 and superconducting (Ba,K)Fe2As2
• Spin reorientation in Na-doped BaFe${}_2$As${}_2$ studied by neutron diffraction
• Short-range cluster spin glass near optimal superconductivity in BaFe${}_{2-x}$Ni${}_x$As${}_2$
• The evolution of antiferromagnetic susceptibility to uniaxial pressure in Ba(Fe{1-x}Co{x})2As2