Table showed the dielectric properties of the samples With the
For the rheological studies, the ceramic powder was made into viscous slurry using 50:50 mixture of ethanol–xylenes solvent system. In order to get well-flocculated slurry in tape casting process, dispersant plays a crucial role. In the present study, we used fish oil (Arjuna Natural Extracts, Kerala, India) as the dispersant. In order to optimize the dispersant amount, we prepared ceramic slurry with varying amount of dispersant (0.5–2.0 wt.%) with respect to powder while keeping the powder loading at a fixed high value of 70 wt.%. The viscosity of the slurry was measured using a rheometer (Brookfield, R/S Plus, MA, USA), and the sedimentation analysis was carried out in a 10 ml graduated measuring cylinder. The initial height (H0) and AC 55649 height (H) at different time interval were noted. The final tape casting slurry was prepared in two stages. In the first step, precalculated amount of ceramic powder was mixed with solvent and dispersant which was ball milled for 24 h. In the second stage, a binder (polyvinyl butyral (PVB), Butvar B-98, Sigma–Aldrich), plasticizers (butyl benzyl phthalate, Sigma–Aldrich, polyethylene glycol, Sigma–Aldrich), and a homogenizer (cyclohexanone, Sigma–Aldrich) were added to synaptic cleft and further ball milled for 24 h. The final homogenized slurry was degassed and casted into thin tapes using a tape-casting machine (Keko equipment, Zuzemberk, Slovenia). The casting was carried out on a silicon coated Mylar® film using double doctor blade technique. The casted tape was then allowed to dry at room temperature for 24 h .