$^{14}$N Nuclear Magnetic Resonance and Relaxation in the Paramagnetic Region of Uranium Mononitride

The spin susceptibility of a polycrystalline sample of uranium mononitride UN is studied by measuring the $^{14}$N NMR line shift, spin-lattice relaxation rates of the nuclear spin, and static magnetic susceptibility in the temperature region of $1.5T_{\text{N}}<T<7T_{\text{N}}$ A joint analysis of the results obtained has revealed the temperature dependence of the characteristic energy of spin fluctuations of the uranium $5f$ electrons: $\Gamma_{\text{nmr}}(T)\propto T^{0.54(4)}$ close to the dependence $\Gamma(T)\propto T^{0.5}$ characteristic of concentrated Kondo systems above the coherent state formation temperature.