Low temperature point contact spectroscopy and transport measurements on filled skutterudite compounds

Several members of the RPt
₄
Ge
₁₂
skutterudites class (R = Sr, Ba, Th, La, Pr) show at low temperature the phenomenon of superconductivity, with R = Pr exhibiting the highest transition temperature of about 8 K. PrPt
₄
Ge
₁₂
shows as well a wide variety of strongly correlated electron behavior, including metal-insulator transitions, spin fluctuations, and various magnetically ordered states. In this work, we have applied the point contact spectroscopy to investigate the superconducting order parameter of the PrPt
₄
Ge
₁₂
compound. Superconductivity in PrPt
₄
Ge
₁₂
is progressively suppressed by partially substituting the Pr ions with Ce ions. For this reason, electrical resistance measurements as a function of the temperature (R-T), in different applied magnetic fields have also been performed and analysed on Pr
_1-x
Ce
_x
Pt
₄
Ge
₁₂
samples for x = 0, 0.07, 0.10.