Magnetic competition in Fe-based germanide and silicide superconductors

P. Villar Arribi (1) , F. Bernardini (2) , L. De’ Medici (3) , Pierre Toulemonde (4) , Sophie Tencé (5) , Andrés Cano (6)

1 ESRF - European Synchrotron Radiation Facility
2 UniCa - Università degli Studi di Cagliari = University of Cagliari
3 ESPCI Paris - Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris
4 NEEL - MRS - Matériaux, Rayonnements, Structure
5 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
6 NEEL - TMC - Théorie de la Matière Condensée

We address the ferromagnetic tendencies detrimental for superconductivity that are related to the substitution of the pnictogen As atom with Ge or Si, together with additional substitutions in the spacer layers in 122 and 1111 Fe-based superconductors. Intermediate compounds in which these substitutions are realized individually are studied within density functional theory. We thus single out the control of spacer ions as an effective way to handle such a ferromagnetism, and we also show that it is suppressed in YFe2Ge2 under pressure —which then can be expected to enhance its superconductivity.

Domaines: Matière Condensée [cond-mat]

P. Villar Arribi, F. Bernardini, L. De’ Medici, Pierre Toulemonde, Sophie Tencé, et al.. Magnetic competition in Fe-based germanide and silicide superconductors. EPL - Europhysics Letters, 2020, 128 (4), pp.47004. ⟨10.1209/0295-5075/128/47004⟩. ⟨hal-02466135⟩