Correlation between carrier mobility and effective mass in Sr2RuO4–xFx (x = 2) under uniaxial strain using the Yukawa screened PBE0 hybrid functional

Abstract

We have investigated the electronic and thermoelectric features (carrier mobilities, scattering rates, etc.) of Sr2RuO4 and Sr2RuO4-xFx (x = 2) by combining computational approaches with experimental results reported in the pertinent literature. The electronic investigation has indicated a metallic character of Sr2RuO4 (Eg = 0 eV), but that the incorporation of fluorine opens the band gap. The findings suggest that Sr2RuO4-xFx (x = 2) is an indirect semiconductor (Eg = 1.55 eV), and that the electronic band gap can be tuned by applying an external compressive or tensile strain (CTS). The relative stability of the compound and the feasibility of its synthesis are firmly proved by positive phonon frequencies and negative cohesive energies. Moreover, electron and hole mobilities in strained and unconstrained Sr2RuO2F2 have been simulated through the Yukawa screened PBE0 hybrid functional (YS-PBE0). It is observed that carrier mobilities are very responsive to strain and can be enhanced or attenuated under pressure or uniaxial stretch. The effective masses of light and heavy holes are greater than those of the electrons, and exhibit opposite behavior to that of carrier mobilities. Under moderate strain and regardless of the process type, Sr2RuO2F2 maintains n-type conducting behavior.