Beyer's non-linearity parameter (B/A) in benzylidene aniline Schiff base liquid crystalline systems

► The Bayer's non-linearity parameter (B/A) is estimated for the first time for a number liquid crystal materials of the type N-(p-n-alkoxy benzylidene)-p-nalkyl anilines. ► The magnitude of B/A estimated from sound velocity data is higher compared to that estimated thermal expansion data. ► The B/A value decreases with increase in molecular weight with an even odd fashion and reaches a minimum value and saturates. ► These studies reveal that both the thermal expansion coefficient and sound velocity are the tools to estimate the non-linear parameter B/A in the case of liquid crystals.