Scanning mode of the upgraded FTS-14 Digilab spectrometer - study of 8*OCBpolymorphism

Polymorphism. of the right-handed octyloxycyanobiphenyl, (S)-4-(1-methylhep tyloxy)-4 ' -cyanobiphenyl (8*OCB), was studied by means of the upgraded FF IR spectrometer DIGILAB FTS-14. Far infrared absorption spectra were record ed in the frequency range of 50-500 cm(-1) for the sample temperature from 50 to 310 K. Two crystalline phases (metastable and stable) were detected. The acquisition system of the upgraded spectrometer enables real-time traci ng and recording the maxima of single interferograms vs time and correlate them to the temperature of the sample. The work demonstrates the advantage of this feature of the spectrometer while studying the phase transitions an d long-time relaxations in molecular crystals. (C) 2001 Elsevier Science B. V. All rights reserved.