Single crystals of the complex perovskite Pb(Fe2/3W1/3)O3 (PFW), synthesized by high-temp. soln. growth, have been studied by optical and dielec. characterizations at zero field and under an elec. bias field. At zero elec. field, the PFW crystals remain optically isotropic down to 10 K, and that the diffuse max. of the permittivity near 178 K results from a typical dielec. relaxation with strong frequency dispersion. Application of an elec. field can induce a macroscopically polar phase, which remains metastable when removing E at low temps. Reversing the polarity of the applied field leads to a reversal of the induced polarization Pind, giving rise to a dielec. hysteresis loop of ferroelec. character. Thus, the ferroelectricity in PFW results in reality from the induction of the macropolar phase. The coercive field for the establishment of the induced polarization increases sharply with decreasing temp. Switching of the induced polar states have been evidenced and the induced birefringence measured by means of simultaneous optical examns. with polarized light microscopy. It is expected that the magnetoelec. effect can be detected in such an induced ferroelec. phase in PFW. [on SciFinder (R)]