Strong coupling between magnetic and structural order parameters in SrFe2As2

A. Jesche; N. Caroca-Canales; H. Rosner; H. Borrmann; A. Ormeci; D. Kasinathan; K. Kaneko; H. H. Klauss; H. Luetkens; R. Khasanov; A. Amato; A. Hoser; C. Krellner; C. Geibel

doi:10.1103/physrevb.78.180504

arXiv · 0807.0632

Strong coupling between magnetic and structural order parameters in SrFe2As2

A. Jesche·N. Caroca-Canales·H. Rosner·H. Borrmann·A. Ormeci·D. Kasinathan·K. Kaneko·H. H. Klauss·H. Luetkens·R. Khasanov·A. Amato·A. Hoser·C. Krellner·C. Geibel

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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.

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A. Jesche, N. Caroca-Canales, H. Rosner, H. Borrmann, A. Ormeci, D. Kasinathan, K. Kaneko, H. H. Klauss, H. Luetkens, R. Khasanov, A. Amato, A. Hoser, C. Krellner, C. Geibel. 2008-07-03. Strong coupling between magnetic and structural order parameters in SrFe2As2. https://doi.org/10.1103/physrevb.78.180504

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