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arXiv · 1703.05180

Homogeneity range of ternary 11-type chalcogenides Fe$_{1+y}$Te$_{1-x}$Se$_x$

Cevriye Koz·Sahana Rößler·Steffen Wirth·Ulrich Schwarz
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Abstract

The 11-type Fe-chalcogenides belong to the family of Fe-based superconductors. In these compounds, the interstitial Fe is known to strongly influence the magnetic and superconducting properties. Here we present the chemical homogeneity range of ternary compounds Fe$_{1+y}$Te$_{1-x}$Se$_x$ based on powder x-ray diffraction, energy dispersive x-ray analysis and magnetization measurements. Our investigations show that the maximum amount of excess Fe in homogeneous Fe$_{1+y}$Te$_{1-x}$Se$_x$ decreases with increase in Se substitution for Te. Using our synthesis procedure, single-phase Fe$_{1+y}$Te$_{1-x}$Se$_x$, with $~0.5 \leq x <~1$ could not be formed for any amount of excess Fe. Further, the superconducting volume fraction in the material is found to be strongly suppressed by excess Fe.

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Cevriye Koz, Sahana Rößler, Steffen Wirth, Ulrich Schwarz. 2017-03-15. Homogeneity range of ternary 11-type chalcogenides Fe$_{1+y}$Te$_{1-x}$Se$_x$. https://doi.org/10.1007/s10948-016-3632-x

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