Effect of Hydrostatic Pressure on the Ferroelectric Phase Transition in Diglycine Nitrate

Effect of hydrostatic pressure on the ferroelectric phase transitions in glycine silver nitrate (NH 2 CH 2 COOH·AgNO 3 ; GSN) and its deuterated analogue(DGSN) was studied by means of dielectric measurements. The Curie temperatures decrease with increasing pressure by a relation T c = T c 0 + K p +γ p 2 . Parameters T c 0 , K , and γ are determined as -57.1°C, -17.1 deg kbar -1 , and 1.3 deg kbar -2 , respectively, for GSN and -42.7°C, -20.2 deg kbar -1 , and 1.7 deg kbar -2 , respectively, for DGSN. Considerable decrease in Curie constants was observed both in GSN and in DGSN as pressure increases.