Raman and Birefringence Studies on the Incommensurate Phase Transition of Bis(4-chlorophenyl) sulfone Crystal

概要

論文の詳細を見る
Temperature dependences of polarized I<aman spectra and birefringence of bis(4-chlorophenyl)sulfone (BCPS) crystal were measured. Gas-phase Raman spectra ofBCPS w'ere also xaaeasured. Raman bancls observed in the low-frequency region atroom temperature were shown to have partial nature of intramolecular vibrations.The lowest-frequency Raman band observed at low tenaperatures softened as the fern-perature was raised up to T,= 150 K. A gradual cltange of birefringence wets also ob-served below T . Tltese are in laarmony with previous reports c>n tlte norn?al-incom-mensurate phase transition of this crystal at T,. Tlte critical expc>nents for Late changesin the soft-nvode frequency and the birefringence were compared witla tltat for thepreviously reported intensity change of the satellite X-ray diffraction. Tlaese data wereexplained by assuming an incommensurate orientational naodulation of tlte phenylgroups of BCPS molecules. However, the incommeuasurate-conanaensurate transitionwhich Baas been expected to take place around 115 K was not detected by tlae presentnaeasurements.phase transition, incommensurate, Ranaan spectra, soft mode, birefrix'ngexace
社団法人日本物理学会の論文
1992-07-15