Study by hysteresis measurements of the influence of grain size on the dielectric properties of ceramics of the Sr0.4Ba0.60TiO3 type prepared under different sintering conditions

The ferroelectric properties of the Ba0.6Sr0.4TiO3 system prepared at 1250, 1350 and 1450 degrees C sintering temperatures for up to 4 h, are studied through the measurements of the hysteresis loops at different temperatures and at a constant field of 40 kV/m. Grain size analysis was performed with a scanning electron microscope (SEM) with a statistical method, The dielect ric properties of the samples are reported as a function of temperature for the different sintering conditions. The dielectric permittivity and the re manent polarization are correlated to the grain size distributions obtained by SEM. A derivative process of the remanent polarization is used to analy ze the phase transitions as the temperature is varied. (C) 1999 Published b y Elsevier Science Ltd. All rights reserved.