Non-Debye dielectric dispersion of barium titanate stannate in the relaxor and diffuse phase-transition state

Frequency dependence T-m(f ) of the permittivity maximum temperature observed in BaTi(1-x)Sn(x)0(3), x=0.2 (BTS20), confirms that this composition is close above threshold x(c) for relaxor behavior in BTS. The low-frequency permittivity carries a ln(1/f )-frequency dependence in the vicinity of T-m, both for x=0.2 and x=0.125<x(c). At temperatures T<T-m, the non-Debye contribution of both compositions shows a qualitatively different temperature dependence, indicating basic differences between the diffuse phase-transition state and the relaxor state of BTS. (C) 2004 American Institute of Physics.