First-order magnetic and structural phase transitions inFe1+ySexTe1−x

2008/11/02 by Shiliang Li, Clarina de la Cruz, Clarina dela Cruz +13 · 2 citations
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Rare-earth and actinide compounds #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.79.054503

published as Phys. Rev. B 79, 054503 (2009) · 5 pages, 3 figures

arxiv created 2008/11/02 · openalex publication_date 2009/02/02 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

We use bulk magnetic susceptibility, electronic specific heat, and neutron scattering to study structural and magnetic phase transitions in Fe_1+ySe_xTe_1\ensuremath-x. Fe_1.068Te exhibits a first-order phase transition near 67 K with a tetragonal-to-monoclinic structural transition and simultaneously develops a collinear antiferromagnetic (AF) order responsible for the entropy change across the transition. Systematic studies of the FeSe_1\ensuremath-xTe_x system reveal that the AF structure and lattice distortion in these materials are different from those of FeAs-based pnictides. These results call into question the conclusions of present density-functional calculations, where FeSe_1\ensuremath-xTe_x and FeAs-based pnictides are expected to have similar Fermi surfaces and therefore the same spin-density wave AF order.

Citations

• Competing orders and spin-density-wave instability in La(O 1−x F x )FeAs

Cited by

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• Anomalous dependence ofc-axis polarized FeB1gphonon mode with Fe and Se concentrations in Fe1+yTe1−xSex