Be-NMR studies of the heavy-fermion superconductor UBe

To, Hideki*; Tsugawa, Norihiko*; Sera, Masafumi*; Haga, Yoshinori   ; Onuki, Yoshichika

Field-angle dependence of Be-NMR measurements has been carried out for a single crystal UBe in the temperature range of 0.35-1.5 K. For the [001] direction, we observed that Be-NMR spectra consisted of 10 lines; one line comes from a Be(I) site located in the cubic symmetry, while nine lines come from Be(II) sites located in the lower symmetry. From the field angle dependence of the NMR spectra, we determined NQR parameters. In the superconducting state, we found that Be-NMR Knight shift for [001] direction does not change at all. This result is consistent with the spin triplet pairing state in UBe.