Using an impedance technique we measured the electrical properties in Bi(4-
x)Ln(x)Ti(3)O(12) (Ln = Gd, Dy), with 0 < x < 1. Aurivillius solid solution
s. These systems show ferroelectric behavior for small values of x and beco
me relaxor for large values of x (x > 0.2). We present results of the elect
ric susceptibility vs. frequency and also vs. temperature. For the dysprosi
um solid solution (from x = 0.4 to 0.8. above 550 degreesC) we observed imp
ortant changes in the activation energy as a function of temperature. The i
mpedance measurements were done from room temperature to 850 degreesC. The
solid-solution samples for x values up to 1 were prepared by the solid-solu
tion reaction method. Characterization of the samples by X-ray powder diffr
action technique indicate that the single phase has an orthorhombic unit ce
ll. (C) 2001 Elsevier Science B.V. All rights reserved.