Novel phase transition and the pressure effect in YbFe2Al10-type CeT2Al10 (T=Fe, Ru, Os)

TL;DR

This study reports the growth of single crystals of CeT2Al10 compounds, investigates their pressure-induced phase transitions, and reveals their heavy fermion behavior and gap formation, highlighting a scaling relation in their pressure-dependent properties.

Contribution

First successful growth of CeT2Al10 single crystals and comprehensive analysis of their pressure effects and phase transitions.

Findings

CeT2Al10 compounds are heavy fermion systems.

Pressure induces a sudden disappearance of T0 and transforms CeRu2Al10 into a Kondo insulator.

Partial gap opens over Fermi surfaces below T0.

Abstract

We have succeeded in growing single crystals of orthorhombic CeT2Al10 (T=Fe, Ru, Os) by Al self-flux method for the first time, and measured the electrical resistivity at pressures up to 8 GPa, the magnetic susceptibility and specific heat at ambient pressure. These results indicate that CeT2Al10 belongs to the heavy fermion compounds. CeRu2Al10 and CeOs2Al10 show a similar phase transition at T0 = 27.3 and 28.7 K, respectively. The temperature dependences in the ordered phases are well described by the thermally activated form, suggesting that partial gap opens over the Fermi surfaces below T0. When pressure is applied to CeRu2Al10, T0 disappears suddenly between 3 and 4 GPa, and CeRu2Al10 turns into a Kondo insulator, followed by a metal. The similarity of CeT2Al10 under respective pressures suggests a scaling relation by some parameter controlling the unusual physics in these compounds.