Multipole and superconducting state in PrIrZn probed by muon spin relaxation

Higemoto, Wataru  ; Ito, Takashi   ; Ninomiya, Kazuhiko; Onimaru, Takahiro*; Matsumoto, Keisuke*; Takabatake, Toshiro*

We performed muon spin rotation and relaxation measurements (SR) in caged structural heavy fermion system PrIrZn to elucidate magnetic and superconducting properties. Temperature independent SR spectra were observed below 1K, indicating that the phase transition at 0.11K is non-magnetic origin, most probably pure quadrupole ordering. In the superconducting phase, no sign of unconventional superconductivity, like a broken time reversal symmetry superconductivity, is seen below =0.05K. Moreover, we have observed spontaneous muon spin precession in a zero field in the paramagnetic phase below 15K, suggesting a novel coupling between Pr nuclei and muon realize in PrIrZn.