1982 Volume 90 Issue 1048 Pages 709-714
The Effect of grain orientation on dielectric properties of a ferroelectric BaBi4Ti4O15 ceramic thick film fabricated by a modified doctor blade method was investigated. For evaluation of the grain orientation, the equation f=P0(Whklt-1)/(1-P0) proposed by Zhang was fully examined and the degree of orientation F was newly defined. The F value for each crystal plane was calculated from an X-ray diffraction pattern, which was further correlated with the measured permittivity and dielectric loss (tanδ). The diffraction intensity of the crystal planes perpendicular to c-axis such as (008) and (0010) was observed to be higher than that for a non-oriented sample and resulted in F>0. The intensity of the crystal planes parallel to c-axis such as (020), on the other hand, was lower, resulting in F<0. The permittivity of a film was smaller than that of a normally sintered specimen in the temperature range 15°-480°C. It was concluded that the permittivity along c-axis was smaller than that along a- or b-axis for BaBi4Ti4O15.
