BRILLOUIN-SCATTERING STUDY OF THE ELASTIC-CONSTANTS OF PHENOTHIAZINE THROUGH THE PHASE-TRANSITION - REPLY

Disagreement in the ordering of relative magnitudes of the elastic con stants of phenothiazine with those of Ecolivet et al. is resolved. Dub ious methodologies and assumptions employed by Ecolivet et al. in thei r measurements, approximations, and arguments [C. Ecolivet er al., Phy s. Rev. B 44, 5185 (1991)] are noted. Samples employed by these invest igators in both their ultrasonic and Brillouin measurements are shown to exhibit properties consistent with impure samples and inconsistent with those of Sartwell and Eckhardt.