Electrical resistivity of the heavy-fermion-filled cage compoundCe3M4Sn13(M=Co,Rh,Ru)under high pressure

Abstract

The effect of pressure on electrical resistivity of heavy-fermion compounds ${\mathrm{Ce}}_{3}{M}_{4}{\mathrm{Sn}}_{13}$, where $M=\mathrm{Co}$, Rh, Ru, and the ${\mathrm{La}}_{3}{M}_{4}{\mathrm{Sn}}_{13}$ counterparts is studied in the framework of the fully relativistic full potential local orbital method. The experiment shows that the electrical resistivity of ${\mathrm{Ce}}_{3}{\mathrm{Co}}_{4}{\mathrm{Sn}}_{13}$ and ${\mathrm{Ce}}_{3}{\mathrm{Rh}}_{4}{\mathrm{Sn}}_{13}$ increases with pressure, a similar pressure effect is obtained for isostructural La-based reference metals, while opposite behaviors under pressure are documented for ${\mathrm{Ce}}_{3}{\mathrm{Ru}}_{4}{\mathrm{Sn}}_{13}$ and ${\mathrm{La}}_{3}{\mathrm{Ru}}_{4}{\mathrm{Sn}}_{13}$. The contrasting pressure dependent effects of ${\mathrm{Ce}}_{3}{\mathrm{Co}}_{4}{\mathrm{Sn}}_{13}$ and ${\mathrm{Ce}}_{3}{\mathrm{Ru}}_{4}{\mathrm{Sn}}_{13}$ are discussed. In order to clarify the various phenomena the band-structure calculations under applied pressure were performed. Here, we show that the resistivity increase with pressure arises from the formation of interband distances at the Fermi level in ${\mathrm{Ce}}_{3}{\mathrm{Co}}_{4}{\mathrm{Sn}}_{13}$, this pseudo-gap-like effect is also pressure dependent, while in ${\mathrm{Ce}}_{3}{\mathrm{Ru}}_{4}{\mathrm{Sn}}_{13}$ the opposite change of resistivity results from the suppression of spin fluctuations under pressure.