Induced and spontaneous optical activity in Pb5Ge3O11 single crystals

摘要: Abstract Temperature dependences of the optical rotatory power ρs 3 in ferroelectric phase, field-induced ρ3(E 3) paraelectric phase and initial permittivity e33 have been measured. These results show that dρ3/dE fulfils Curie-Weiss law being proportional to value e33. The electrogyration coefficient y333=0.77×10−3 m2C−1 as determined from measurements agrees well with coefficients obtained spontaneous values es 3, P3s. 3(T) data region between Tc · K room temperature are described by empirical relation: ∼ (Tc−T)0.35