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arXiv · 1102.1933

Magnetoelastic Coupling in the Phase Diagram of Ba1-xKxFe2As2

Sevda Avci·Omar Chmaissem·Eugene A. Goremychkin·Stephan Rosenkranz·John-Paul Castellan·Duck-Young Chung·Ilya S. Todorov·John A. Schlueter·Helmut Claus·Mercouri G. Kanatzidis·Aziz Daoud-Aladine·Dmitry Khalyavin·Raymond Osborn
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Abstract

We report a high resolution neutron diffraction investigation of the coupling of structural and magnetic transitions in Ba1xKxFe2As2. The tetragonal-orthorhombic and antiferromagnetic transitions are suppressed with potassium-doping, falling to zero at x <~ 0.3. However, unlike Ba(Fe1xCox)2As2, the two transitions are first-order and coincident over the entire phase diagram, with a biquadratic coupling of the two order parameters. The phase diagram is refined showing that the onset of superconductivity is at x = 0.133 with all three phases coexisting until x >~ 0.24.

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Sevda Avci, Omar Chmaissem, Eugene A. Goremychkin, Stephan Rosenkranz, John-Paul Castellan, Duck-Young Chung, Ilya S. Todorov, John A. Schlueter, Helmut Claus, Mercouri G. Kanatzidis, Aziz Daoud-Aladine, Dmitry Khalyavin, Raymond Osborn. 2011-02-09. Magnetoelastic Coupling in the Phase Diagram of Ba1-xKxFe2As2. https://doi.org/10.1103/physrevb.83.172503

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