Dielectric properties of TGS and TGFB monocrystals under high pressure

Abstract
The Ps, Ec and Tc under high pressure in TGS and TGFB crystals in the range up to 25 kbar were investigated. At pressures up to 10-14 kbar the shift of the Curie point is linear with dTc/dp = 2.4°K/kbar. At higher pressures a nonlinear increase in Tc has been observed. It is associated with hindered rotation of the NH3 groups. The effect of pressure on the spontaneous polarization is greater than that resulting from a single displacement of TC vs. p.