H-1-NMR OBSERVATION OF THE CRITICAL SLOWING-DOWN IN AMMONIUM-CHLORIDE- COMMENT

K. W. Lee et al. have reported the NMR measurements on ammonium chlori de near the lambda transition temperature [Phys. Rev. B 52. 16028 (199 5)]. Unfortunately, the second moment values given in their paper diff er completely from the same values published by many authors during th e last 40 years, We give here the correct values of the second moment. measured and calculated from the crystal structure. We also discuss t he possible reason for errors in the commented paper.