Spin-lattice relaxation of 25 Al and 28 P in Pt

The spin-lattice relaxation times T 1 for short-lived β emitters 25Al(I = 5/2, T 1/2 = 7.2 s) and 28P(I = 3, T 1/2 = 270 ms) in Pt were measured by means of the β-NMR technique. As a result, T 1[25Al in Pt] = (1.1 $^{+\ 0.7}_{-\ 0.3})$ s and T 1[28P in Pt] >0.5 s were obtained at temperatures of 17 and 20 K, respectively. The Knight shifts were estimated from the Korringa relation, which were evaluated by comparing to the first principle calculations.