Evolution of crystalline electric field effects, superconductivity, and heavy fermion behavior in the specific heat of Pr(Os${}_{1-x}$Ru${}_x$)${}_4$Sb${}_{12}$

Abstract

Specific heat $C(T)$ measurements were made on single crystals of the superconducting filled skutterudite series Pr(Os${}_{1-x}$Ru${}_x$)${}_4$Sb${}_{12}$ down to 0.6 K. Crystalline electric field fits in the normal state produced parameters which were in agreement with previous measurements. Bulk superconductivity was observed for all values of the Ru concentration $x$ with transition temperatures consistent with previous experiments, confirming a minimum in $T_c$ at $x=0.6$. The $C(T)$ data below $T_c$ appear to be more consistent with power law behavior for $x=0$ (PrOs${}_4$Sb${}_{12}$), and with exponential behavior for $0.05\le x\le 0.2$. An enhanced electronic specific heat coefficient $\gamma$ was observed for $x\le 0.4$, further supporting $x\simeq 0.6$ as a critical concentration where the physical properties abruptly change. Significant enhancement of $\Delta C/T_c$ above the weak coupling value was only observed for $x=0$ and $x=0.05$.

arXiv comment16 pages, 5 figures, submitted to Physical Review B. v2: text added and figures modified

References in corpus (16)

• Time-Reversal Symmetry-Breaking Superconductivity in Heavy Fermion PrOs4Sb12 detected by Muon Spin Relaxation
• Multiple Superconducting Phases in New Heavy Fermion Superconductor PrOs4Sb12
• Thermodynamical Study on the Heavy-Fermion Superconductor PrOs4Sb12: Evidence for Field-Induced Phase Transition
• Evidence for Unconventional Strong-coupling Superconductivity in PrOs_4Sb_12 : An Sb Nuclear Quadrupole Resonance (NQR) Study
• Low temperature specific heat of the heavy fermion superconductor PrOs${}_4$Sb${}_{12}$
• The Crystal Field Potential of PrOs4Sb12: Consequences for Superconductivity
• Probing the superconducting gap symmetry of PrOs${}_4$Sb${}_{12}$: A penetration depth study
• muSR linewidth and isotropic pairing in superconducting PrOs4Sb12
• Field Dependence of Electronic Specific Heat in Two-Band Superconductors
• Very Low Temperature Tunnelling Spectroscopy in the heavy fermion superconductor PrOs${}_4$Sb${}_{12}$
• Superconductivity and crystalline electric field effects in the filled skutterudite series Pr(Os${}_{1-x}$Ru${}_x$)${}_4$Sb${}_{12}$
• Sb-NQR probe for superconducting property in the Pr-based filled skutterudite compound PrRu4Sb12
• High magnetic field phase diagram of PrOs4Sb12
• Probing the superconducting gap symmetry of PrRu${}_4$Sb${}_{12}$: A comparison with PrOs${}_4$Sb${}_{12}$
• Superconductivity and the high field ordered phase in the heavy fermion compound PrOs${}_4$Sb${}_{12}$
• Mixed-parity superconductivity in centrosymmetric crystals

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• Three-Dimensional Majorana Fermions in Chiral Superconductors
• Schottky anomaly and short-range antiferromagnetic correlations in filled skutterudites Pr${}_{1-x}$Eu${}_x$Pt${}_4$Ge${}_{12}$
• Eliashberg theory of superconductivity and inelastic rare-earth impurity scattering in filled skutterudite La${}_{1-x}$Pr${}_x$Os${}_4$Sb${}_{12}$
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