Anisotropic electrical resistivity of LaFeAsO: evidence for electronic nematicity

Abstract

Single crystals of LaFeAsO were successfully grown out of KI flux. Temperature dependent electrical resistivity was measured with current flow along the basal plane, ρ_perpend(T), as well as with current flow along the crystallographic c-axis, ρ_parallel(T), the latter one utilizing electron beam lithography and argon ion beam milling. The anisotropy ratio was found to lie between ρ_parallel/ρ_perpend = 20 - 200. The measurement of ρ_perpend(T) was performed with current flow along the tetragonal [1 0 0] direction and along the [1 1 0] direction and revealed a clear in-plane anisotropy already at T \leq 175 K. This is significantly above the orthorhombic distortion at T_0 = 147 K and indicates the formation of an electron nematic phase. Magnetic susceptibility and electrical resistivity give evidence for a change of the magnetic structure of the iron atoms from antiferromagnetic to ferromagnetic arrangement along the c-axis at T^\ast = 11 K.

10 pages, 6 figures, minor changes

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Cited by in corpus (4)

• Emergence of Orbital Nematicity in the Tetragonal Phase of BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Evolution of the Phase Diagram of LaFeP${}_{1-x}$As${}_x$O${}_{1-y}$F${}_y$ ($y$ = 0 -- 0.1)
• Revisiting the phase diagram of LaFe${}_{1-x}$Co${}_x$AsO on single crystals by thermodynamic methods
• Crossover between magnetism and superconductivity in low H-doped LaFeAsO