Temperature-dependent studies in some homologues of alkyloxy cyanobiphenylemploying positron lifetime spectroscopy

Some homologues of alkyloxy cyanobiphenyl (6OCB, 8OCB, 9OCB, 10OCB) have be en investigated by employing positron Lifetime spectroscopy. In each of the se compounds, temperature dependent positron lifetime measurements have bee n carried out, both in the heating as well as cooling cycles. Besides detec ting many interesting features like solid-crystalline polymorphism, anti-pa rallel bimolecular association, formation of cybotactic groups in the nemat ic phase,, positron annihilation parameters have been able to reveal anomal ous structural changes taking place in these compounds.