TEMPERATURE-DEPENDENT STUDIES IN SOME HOMOLOGUES OF ALKYLOXY CYANOBIPHENYL EMPLOYING POSITRON LIFETIME SPECTROSCOPY

Abstract

Some homologues of alkyloxy cyanobipheny1 (6OCB, 8OCB, 9OCB, 10OCB) have been investigated by employing positron lifetime spectroscopy. In each of these compounds, temperature dependent positron lifetime measurements have been carried out, both in the heating as well as cooling cycles. Besides detecting many interesting features like solid-crystalline polymorphism, anti-parallel bimolecular association, formation of cybotactic groups in the nematic phase, positron annihilation parameters have been able to reveal anomalous structural changes taking place in these compounds.