DIELECTRIC AND MECHANICAL PROPERTIES OF A NON LINEAR OPTICAL CRYSTAL: ANTIMONY POTASSIUM TARTRATE
Keywords:
APT, crystal growth, slow evaporation technique, dielectric properties, NLO.Abstract
Semi-Organic Antimony potassium tartrate (APT) single crystals were grown successfully from the
aqueous solution by slow evaporation technique at room temperature. The dielectric behaviour of the sample was studied
over the frequency range from 50 Hz to 5 MHz at the temperatures 40°C, 50°C, 60°C, 70°C and 80°C. The values of
dielectric constant and dielectric loss decrease with the increase in frequency. Higher dielectric permittivity at low
frequency with very low losses makes this crystal more attractive for optoelectronic and NLO applications. Vickers
microhardness analysis was carried out to identify the mechanical stability of the grown crystal and the reverse
indentation size effect was explained satisfactorily. The work hardening coefficient (Meyer’s index), yield strength and
the elastic stiffness constant were also calculated. This study confirms that the APT crystal belongs to soft material
category. The non-linear optical (NLO) test confirms the second harmonic signal generation in the grown sample.
