Magnetic moments of ${}^{76}\mathrm{As}$ and ${}^{77}\mathrm{As}$

The nuclear magnetic moments of the ground states of ${}^{76}\mathrm{As}$ and ${}^{77}\mathrm{As}$ were measured using nuclear magnetic resonance on oriented nuclei (NMR-ON) by detecting $\gamma$ rays and $\beta$ rays. The magnetic hyperfine splitting frequencies of ${}^{76}\mathrm{As}\mathrm{Fe}$ and ${}^{77}\mathrm{As}\mathrm{Fe}$ in a zero external magnetic field are 117.99(8) MHz and 225.58(8) MHz, respectively. With the known hyperfine field of $B_{\mathrm{hf}}{(}^{75}\mathrm{As}Fe)=34.29\mathrm{}(3)\mathrm{}\hspace{0.5em}\mathrm{T}$ the magnetic moments have been determined as $\mu {(}^{76}\mathrm{As}{,2\mathrm{}}^{-})=(-\left)0.9028\mathrm{}\right(10)\mathrm{}{\mu }_N$ and $\mu {(}^{77}\mathrm{As}{,3/2\mathrm{}}^{-})=+1.2946\mathrm{}(13)\mathrm{}{\mu }_N.$ The effective spin-lattice relaxation time for ${}^{76}\mathrm{As}\mathrm{Fe}$ has been measured to be 5.2(8) m and 11.2(16) m at the external magnetic field of 0.2 T and 0.6 T, respectively. The observed magnetic moments are discussed in the framework of the configuration mixing model.