High-quality single crystals of Pr ( Os1 - x Rux )4 Sb12 were grown by the Sb self-flux method. Magnetic susceptibility χ ( T ) was measured precisely. The characteristic temperature Tmax, where χ ( T ) exhibits a maximum, varies as a function of Ru-content x but its functional form changes at around x = 0.6 where competition of two types of superconductivity is suggested. Since Tmax is thought to be relevant to the splitting energy between a ground state and a first excited state, we analyzed χ ( T ) considering the crystalline electric field (CEF) of the Th symmetry. χ ( T ) is well fitted assuming a Γ1 singlet ground state for all x values. As expected from Tmax, the energy of the first excited state ( Γ4( 2 )) changes its functional form at around x = 0.6. Furthermore, the energies of the second and third excited states ( Γ4( 1 ) and Γ23) exhibit a minimum at almost the same value of x = 0.6. These results suggest that the CEF is related to the superconductivity in Pr ( Os1 - x Rux )4 Sb12.
- Crystalline electric field
- Magnetic susceptibility
- Pr ( Os Ru ) Sb
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering