Proton spin lattice relaxation in single crystal of NaH3(SeO3)2

Proton spin lattice relaxation time in NaH₃(SeO₃)₂ was measured at temperatures 300-77 K at a frequency of 8.01 MHz. Except near the temperatures of the ferroelectric transitions at 196 and 100 K the relaxation rate is governed by paramagnetic impurities, and the formula derived by Blumberg for diffusion-limited case is applicable. A logarithmic divergence above 196 K is related to the anomaly of the dielectric constant in the same temperature range.