Piezoelectricity in Single Crystal of Pentaerythritol Tetranitrate

Abstract

The piezoelectric constants perpendicular to (110) and (001) of single crystal f pentaerythritol tetranitrate (PETN) are determined to be (3.2+-0.30)x10/sup-13/and (1.5+-0.30)x10/sub-13/CN/sub-1/. The charge development on these faces under static loading has been confirmed to be true piezoelectric in origin. The crystal seems to experience a quasi permanent deformation under repeated and successive compression with a very long relaxation time. This gives rise to a unique behaviour of individual crystal of PETN under identical stress condition. Mechanical stress relaxation measurements have also been carried out to provide additional evidence on the uniqueness of the crystal. Dielectric constant of the crystal along the directions perpendicular to (110) and (001) are 3.50+-0.12 and 4.57+-0.17; Young's modulus along the directions are (1.24+- 0.30)x10/sub6/g cm/sup-2/ respectively. Single crystals of one cm/sub3/ of PETN develops about 10 V cm/sup-1/ field under a force of 1 kg across (110)face.