Effect of hydrostatic pressure on the phase transition temperatures and spontaneous polarization of thiourea monocrystals

Hydrostatic pressure-induced shifts in the phase transition temperatures of monocrystalline thiourea are studied. The transition occurring at 202 K under atmospheric pressure is found to shift linearly downwards. The other transitions behave likewise at pressures up to 0.9 kbar. At 0.9 kbar the phase transitions, lying in the temperature interval from 169 to 180 K under atmospheric pressure, vanish. From hysteresis loop observations, the hydrostatic pressure-induced change in spontaneous polarization in the region of phases I and III is determined.