Concentration of Ultrasonic-Velocity Invariant with Respect to Temperature Observed in Alcohol-Water Mixtures

Abstract

The properties of ferroelectric nanodomains in LiNbO 3 crystals were investigated using scanning force microscopy. In particular, we found differences in the domain shape, domain-wall sharpness, and lateral growth rate of domains in nearstoichiometric and congruent LiNbO 3 crystals. In the near-stoichiometric LiNbO 3 crystal, the domain dots are hexagonal and linear domains with smooth walls can be engineered parallel to one of the crystallographic Y-axes. The shape of the linear domains engineered at an angle to the crystallographic Y-axis changes when a small bias is applied during scanning, and various domain shapes are obtained after being stabilized by scanning. However, in the congruent LiNbO 3 crystal, the domain dots are roughly circular and there is no change in the shape of the linear domains, which have rough domain walls. The lateral growth rate of domains in the congruent LiNbO 3 crystal is smaller than that in the near-stoichiometric LiNbO 3 crystal.

Ultrasonic and IR study of molecular association process through hydrogen bonding in ternary liquid mixtures

“…Ultrasonic waves with low amplitude have been used by many scientists to investigate the nature of molecular interactions and physico-chemical behavior of pure, binary, ternary and quaternary liquid mixtures [11][12][13][14][15][16][17][18][19]. A survey of literature [20][21][22][23][24][25][26] indicates that excess values of acoustical parameters are useful in understanding the nature and strength of the molecular interaction in the mixtures.…”

Physico-chemical, acoustic and excess properties of glycylglycine–MnCl2 in aqueous ethanol mixtures at different temperatures

“…As the amino acid and peptide molecules contain functional groups similar to those existing in the more complex proteins, they are expected to mimic some common features of proteins. A number of authors have made contributions in the ultrasonic velocity and density measurements of binary mixtures [12][13][14][15]. In our present study we report viscosity, ultrasonic velocity, density, and refractive index for glycylglycine-MnCl 2 aqueous ethanol mixtures at temperatures T = (288.15 to 318.15) K. Using the ultrasonic velocity and density data, the isentropic compressibility (Ä S ) and excess isentropic compressibility (Ä E S ) values have been evaluated along with viscosity deviations ( Á), molar refraction (R m ), excess molar volume (V E m ), ultrasonic velocity deviation ( u), refractive index deviation ( n D ), intermolecular free length (L f ), specific acoustic impedance (Z) and solvation number (S n ) with a view to investigate the molecular interactions operative in the above said system.…”