Sandra Gilmour

Ultrasonic, piezoelectric and dielectric investigations of (−)-2-α-methylbenzylamino-5-nitropyridine

Abstract Ultrasonic, piezoelectric and dielectric measurements on single crystals of (–)-2-a-α-methylbenzylamino-5-nitropyridine (MBANP) are reported. Longitudinal and transverse velocity measurements in six crystal directions were used to calculate the 13 elastic constants. Dielectric measurements were carried out in four directions and compared with refractive index measurements carried out at optical frequencies. MBANP exhibited piezoelectric coefficients of similar magnitude to those found in lithium niobate. These data are discussed in terms of the intermolecular interactions occurring in the crystal structure.

Ultrasonic and piezoelectric investigations on single crystals of 3-nitroaniline

Abstract Ultrasonic, piezoelectric and thermal expansivity measurements have been carried out using single-crystal samples of 3-nitroaniline (meta-nitroaniline mNA). Longitudinal and transverse velocity measurements in six crystal directions were used to determine the nine elastic coefficients. These data are discussed in relation to the intermolecular interactions existing within the crystal structure of mNA. Piezoelectric measurements show that this organic material exhibits coefficients which are of similar magnitude to those observed for inorganic materials such as lithium niobate.

Synthesis and first hyperpolarizabilities of acceptor-substituted β-apo-8′-carotenal derived compounds

The synthesis and second-order nonlinear optical properties of acceptor-substituted biologically derived β-apo-8′-carotenal compounds are reported; electric field-induced second harmonic generation (EFISH) measurements give values of β(0) which are 2–6 times greater than for 4-N,N-dimethylamino-4′-nitrostilbene (DANS).

Surface acoustic wave propagation in an organic crystalline material

Surface acoustic wave propagation in an acentric low-molar-mass organic crystal, (–)-2-α-methylbenzylamino-5-nitropyridine is described. The relation between various measured physical parameters and the performance of the device is discussed.