Theoretical and experimental investigation of magnetotransport in iron chalcogenides

Federico Caglieris; Fabio Ricci; Gianrico Lamura; Albert Martinelli; A Palenzona; Ilaria Pallecchi; Alberto Sala; Gianni Profeta; Marina Putti

doi:10.1088/1468-6996/13/5/054402

Theoretical and experimental investigation of magnetotransport in iron chalcogenides

Sci Technol Adv Mater. 2012 Nov 26;13(5):054402. doi: 10.1088/1468-6996/13/5/054402. eCollection 2012 Oct.

Authors

Federico Caglieris¹, Fabio Ricci², Gianrico Lamura¹, Albert Martinelli¹, A Palenzona³, Ilaria Pallecchi¹, Alberto Sala³, Gianni Profeta², Marina Putti⁴

Affiliations

¹ CNR-SPIN-Genova corso Perrone 24, 16152, Genova, Italy.
² CNR-SPIN and Department of Physical and Chemical Sciences, University of L'Aquila, Via Vetoio 1, 67100 L'Aquila, Italy.
³ CNR-SPIN-Genova corso Perrone 24, 16152, Genova, Italy; Chemistry and Industrial Chemistry Department, University of Genova, via Dodecaneso 31,I-16146 Genova, Italy.
⁴ CNR-SPIN-Genova corso Perrone 24, 16152, Genova, Italy; Physics Department, University of Genova, via Dodecaneso 33, 16146 Genova, Italy.

Abstract

We explore the electronic, transport and thermoelectric properties of Fe_1+y Se _x Te_1-x compounds to clarify the mechanisms of superconductivity in Fe-based compounds. We carry out first-principles density functional theory (DFT) calculations of structural, electronic, magnetic and transport properties and measure resistivity, Hall resistance and Seebeck effect curves. All the transport properties exhibit signatures of the structural/magnetic transitions, such as discontinuities and sign changes of the Seebeck coefficient and of the Hall resistance. These features are reproduced by calculations provided that antiferromagnetic correlations are taken into account and experimental values of lattice constants are considered in DFT calculations. On the other hand, the temperature dependences of the transport properties can not be fully reproduced, and to improve the agreement between experiment and DFT calculations it is necessary to go beyond the constant relaxation time approximation and take into account correlation effects.

Keywords: Fe based superconductors; Fe1+ySexTe1−x; first-principles density functional theory calculations; magnetotransport properties; thermoelectric properties.