Magnetic phases in superconducting, polycrystalline bulk FeSe samples
Quentin Nouailhetas,
Anjela Koblischka-Veneva,
Michael R. Koblischka,
Pavan Kumar Naik S.,
Florian Schäfer,
H. Ogino,
Christian Motz,
Kévin Berger,
Bruno Douine,
Yassine Slimani,
Essia Hannachi
Affiliations
Quentin Nouailhetas
Institute of Experimental Physics, Saarland University, Campus C 6 3, 66123 Saarbrücken, Germany
Anjela Koblischka-Veneva
Institute of Experimental Physics, Saarland University, Campus C 6 3, 66123 Saarbrücken, Germany
Michael R. Koblischka
Institute of Experimental Physics, Saarland University, Campus C 6 3, 66123 Saarbrücken, Germany
Pavan Kumar Naik S.
Research Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science (AIST), 1-1-1 Central 2, Umezono, Tsukuba, Ibaraki 305-8568, Japan
Florian Schäfer
Experimentelle Methodik der Werkstoffwissenschaften, Saarland University, Campus D 3 4, 66123 Saarbrücken, Germany
H. Ogino
Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548, Japan
Christian Motz
Experimentelle Methodik der Werkstoffwissenschaften, Saarland University, Campus D 3 4, 66123 Saarbrücken, Germany
Kévin Berger
Groupe de Recherche en Energie Electrique de Nancy (GREEN), Université de Lorraine, 54506 Vandvre-lès-Nancy, France
Bruno Douine
Groupe de Recherche en Energie Electrique de Nancy (GREEN), Université de Lorraine, 54506 Vandvre-lès-Nancy, France
Yassine Slimani
Department of Biophysics, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia
Essia Hannachi
Laboratory of Physics of Materials - Structures and Properties, Department of Physics, Faculty of Sciences of Bizerte, University of Carthage, 7021 Zarzouna, Tunisia
The FeSe compound is the simplest high-temperature superconductor (HTSc) possible, and relatively cheap, not containing any rare-earth material. Although the transition temperature, Tc, is just below 10 K, the upper critical fields are comparable with other HTSc. Preparing FeSe using solid-state sintering yields samples exhibiting strong ferromagnetic hysteresis loops (MHLs), and the superconducting contribution is only visible after subtracting MHLs from above Tc. Due to the complicated phase diagram, the samples are a mixture of several phases, the superconducting β-FeSe, and the non-superconducting δ-FeSe and γ-FeSe. Furthermore, antiferromagnetic Fe7Se8 and ferromagnetic α-Fe may be contained, depending directly on the Se loss during the sintering process. Here, we show MHLs measured up to ±7 T and determine the magnetic characteristics, together with the amount of superconductivity determined from M(T) measurements. We also performed a thorough analysis of the microstructures in order to establish a relation between microstructure and the resulting sample properties.
