Dielectric properties of Ba(Ti1-yYy)O3 ceramics

Temperature and frequency dependence of the real (epsilon') and imaginary (epsilon ") parts of the dielectric permittivity of Ba(Ti1-yYy)O-3 (0.028 less than or equal to y less than or equal to 0.258) ceramic samples were studied in the temperature range 12-500 K at 10(2), 10(3), and 10(4), and 10(5) Hz. The permittivity peaks are rounded and frequency dispersive when y > 0.028. The maximum of the rounded peak (epsilon(m)') decreases with an increase in the yttrium concentration. The temperature corresponding to the permittivity maximum is linearly shifted to lower temperatures at a rate of 29 K per molar percent of yttrium when y less than or equal to 0.122, but it remains constant when y greater than or equal to 0.122. The solid solubility limit of 0.122 is confirmed. Typical relaxer behavior was observed and characterized with empirical parameters in Ba(Ti1-yYy)O-3 solid solutions. (C) 1998 American Institute of Physics. [S0021-8979(98)04714-8].