Av. Alex et J. Philip, Ultrasonic measurement of the elastic constants of potassium hydrogen phthalate single crystals, J APPL PHYS, 88(5), 2000, pp. 2349-2351
Many organic crystals with orthorhombic symmetry exhibit electro-optic, fer
roelectric, and triboluminescence properties. The potassium salt of phthali
c acid (KAP), with the formula C8H5O4K, finds application in soft x-ray spe
ctroscopy due to its large d spacing and has been reported to be piezoelect
ric as well. KAP crystallizes into orthorhombic structure with space group
Pca2(1) All nine elastic constants of KAP have been determined by measuring
the velocity of longitudinal and transverse ultrasonic waves propagating a
long different symmetry directions. Velocities have been measured by the ul
trasonic pulse echo overlap technique by injecting waves generated by quart
z transducers through a suitable bonding medium into the crystal. The McSki
min Delta t correction has been applied to determine the velocities accurat
ely. The temperature variation of selected elastic constants over the range
300-420 K has also been measured and reported. (C) 2000 American Institute
of Physics. [S0021-8979(00)07315-1].