Birefringence of Some Nematic Compounds

Abstract
This paper reports the refractive index and density data and discusses the orientational order parameters in the case of the following eight nematic compounds, viz., (1)p(p-ethoxyphenylazo) phenyl valerate, (2) p(p-ethoxyphenylazo)phenyl hexanoate, (3) p(p-ethoxyphenylazo)phenyl heptanoate, (4) p(p-ethoxyphenylazo)phenyl undecylenate, (5) 4,4′-bis(hexyloxy)azoxybenzene, (6) 4,4′-bis(heptyloxy)azoxybenzene, (7) anisylidene-p-aminophenyl acetate, and (8) anisylidene-p-aminophenyl butyrate.