Ferroelectric and optical hysteresis in SBN doped with rare earth elements

Abstract

In Sr0.61Ba0.39Nb2O6 crystals doped with Ce or Tm the dependence of the two-beam coupling gain factor Gamma on an external dc-field E applied after recording shows a hysteresis, which reflects the ferroelectric P - E hysteresis. At coercive fields E-c the sign of Gamma abruptly reverses, i.e. the energy transfer direction between the coupled beams. The field-controlled state of Gamma is stable and stored after turning off the fields. The results are discussed in terms of the electrooptical effect and ferroelectricity in oxygen-octahedra ferroelectrics.