Piezoelectric Properties of Triglycine-Sulphate

Abstract

Since triglycine sulphate crystal is centrosymmetric above the Curie point, the piezoelectricity in the ferroelectric phase is expected to be an “induced” one as in the case of barium titanate, distinct from an “intrinsic” piezoelectricity of rochelle salt. Temperature dependences of piezoelectric constants are measured by using various cuts of crystal, and some experiments on electrostrictive effect above the Curie point are performed as well. We then obtain electrostrictive constants, and the above expectation is confirmed in several points. Moreover, the phase transition is found not to be accompanied by any elastic change. Next, some effects of irradiation by x-ray and γ-ray on the piezoelectric constants are examined, and it will be shown that an irradiation is useful for preventing a diminution of piezoelectricity resulting from growth of antiparallel domains, especially near the Curie point.