DC ELECTRORHEOLOGY OF FLUID SUSPENDING BARIUM-TITANATE IN THE RANGE OF FERROELECTRIC SIZE EFFECTS

Hydrothermally synthesized barium titanate, which was paraelectric, wa s heated at various temperatures. The powder was mixed with silicone o il at 10vol% to measure rheological properties of the suspension witho ut and with de field of 2kV/mm. The electrorheological effect (ER effe ct), the increase in shear stress by the de field, showed a clear depe ndence to the heating temperature. The ER effect took a clear peak on a fluid dispersing powder heated at 700 degrees C. The splitting of 20 0 and 002 X-ray diffractions of that barium titanate was uncertain, al though this diffraction peak became clearly unsymmetrical.