$\text{}^1H$ NMR on $(Ni_xMn_{1-x})_3[Cr(CN)_6]_2 \cdot nH_2O$

We report on $\text{}^1H$ NMR of $(Ni_xMn_{1-x})3[Cr(CN)_6]_2 \cdot 15H_2O$ hexacyanochromates, where x changes from 0 to 1. The decay time constants of the free induction decay signals described by an effective spin-spin relaxation time $T_{2eff}$ obtained from M(t) = $M_0 \text{exp}(t//T_{2eff})$ decrease as the local magnetic moments increase produced by the magnetic transition metal ions at the sites of the resonant $\text{}^1H$ nuclei. The recovery of the magnetization in the spin-lattice relaxation time $(T_1)$ experiments was single-exponential.