Nuclear Polarization in theB11(d,p)B12Reaction. III

New measurements of the nuclear spin-lattice relaxation times of ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ implanted in Au, Pd, and Pt have established lower limits of 60, 185, and 270 sec °K, respectively, of $T_{1}T$ for ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ in these metals. In conjunction with prior measurements of the effective moment of ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ in these metals, these $T_{1}T$ values show that the Knight shift of ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ in Au is positive, while in Pd and Pt it is negative. Using a common enhancement factor in these metals, one finds the value of the ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ magnetic dipole moment to be $\mu =(+{1.00285}_{-0.000\mathrm{}14}^{+0.000\mathrm{}15}){\mu }_N$.