Strong coupling between magnetic and structural order parameters in SrFe2As2

Abstract

X-ray and Neutron diffraction as well as muon spin relaxation and Mössbauer experiments performed on SrFe${}_2$As${}_2$ polycrystalls confirm a sharp first order transition at $T_0=205$,K corresponding to an orthorhombic phase distortion and to a columnar antiferromagnetic Fe ordering with a propagation vector (1,0,1), and a larger distortion and larger size of the ordered moment than reported for BaFe${}_2$As${}_2$. The structural and the magnetic order parameters present an remarkable similarity in their temperature dependence from $T_0$ down to low temperatures, showing that both phenomena are intimately connected. Accordingly, the size of the ordered Fe moments scale with the lattice distortion when going from SrFe${}_2$As${}_2$ to BaFe${}_2$As${}_2$. Full-potential band structure calculations confirm that the columnar magnetic order and the orthorhombic lattice distortion are intrinsically tied to each other.

10 pages, 4 figures

References in corpus (8)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• Superconductivity up to 37 K in (A1-xSrx)Fe2As2 with A=K and Cs
• Lattice and magnetic instabilities in CaFe2As2: A single crystal neutron diffraction study
• Commensurate Spin Density Wave in LaOFeAs: A Local Probe Study
• Magnetic and structural transitions in layered FeAs systems: AFe2As2 versus RFeAsO compounds
• Structural transition and anisotropic properties of single crystalline SrFe2As2
• The effect of internal pressure on the tetragonal to monoclinic structural phase transition in ReOFeAs: the case of NdOFeAs

Cited by in corpus (2)

• Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering
• Lattice and magnetic instabilities in CaFe2As2: A single crystal neutron diffraction study