Dresden 2020 – wissenschaftliches Programm
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TT 54.13: Vortrag
Donnerstag, 19. März 2020, 12:45–13:00, HSZ 201
X-ray absorption spectroscopy measurements of Fe1+xTe — •Jan Fikáček1, Jonas Warmuth2, Fabian Arnold3, Sunil Wilfred4, Cinthia Piamonteze5, Martin Bremholm3, Ján Minár4, Ján Lančok1, Philip Hofmann3, Jens Wiebe2, and Jan Honolka1 — 1Institute of Physics of CAS, Prague, Czech Republic — 2Hamburg University, Hamburg, Germany — 3Aarhus University, Aarhus, Denmark — 4University of West Bohemia, Plzeň, Czech Republic — 5Paul Scherrer Institut, Villigen, Switzerland
Iron based chalcogenides (IBC) have a quasi two-dimensional crystal structure, which is the simplest one among Fe-based superconductors and makes IBC good candidates for both experimental and theoretical studies. FeSe is superconducting below Tc = 8 K  going above 100 K when an FeSe monolayer is grown on SrTiO3 . In contrast, the analog non-superconducting Fe1+xTe has an antiferromagnetic (AFM) ground state varying with the excess Fe concentration x.
Here, we report on results of X-ray absorption spectroscopy measurements of Fe1+xTe with x = 0.094 ordering antiferromagnetically below TN = 62 K. X-ray magnetic circular dichroism up to 7 T scales linearly with the bulk magnetization. Both drop when Fe1.094Te enters the AFM state. In contrary, X-ray magnetic linear dichroism (XMLD) increases monotonically below TN down to lowest temperatures. XMLD data are compared with results of our density functional theory calculations taking into account Fe excess up to x = 1.1.
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