The superconducting characteristics on the itinerant ferromagnetic superconductor UGe2 have been investigated via the 73Ge-NQR measurements under pressure (P) near the critical pressure Px where the first-order transition takes place from the low-temperature (T) and low-P ferromagnetic phase (FM2) to high-T and high-P one (FM1). The measurements of nuclear spin-lattice relaxation rate 1 / T1 have revealed a power-law like behavior as Tn without the coherence peak, whereas at low temperatures, it deviates from the Tn dependence to a T-linear like behavior. These results that depend on the pressure are well understood in terms of non-unitary spin-triplet pairing state where the ferromagnetic up-spin band is gapped, but the down-spin band remains gapless at the Fermi level. We will argue an intimate relationship of the onset of SC with FM1 and FM2.
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