JOURNAL OF MOLECULAR STRUCTURE, cilt.382, sa.1, ss.57-62, 1996 (SCI-Expanded)
In this study we have correlated the frequency shifts of the acoustic modes to the volume changes by means of our gamma-Gruneisen relations near the lambda-phase transitions in NH4Cl. Using the acoustic frequencies and the length-change data for NH4Cl from the literature, we first calculated the Gruneisen gamma values for the LA modes along the (100) and (110) directions and for the TA mode along the (110) direction. We then predicted the acoustic mode frequencies across the lambda-phase transitions in NH4Cl.