Preparation of Y ₃Fe _4.85O ₁₂ ferrite substrates by non aqueous tape casting

Y ₃Fe _4.85O ₁₂ ferrite substrates were fabricated through non aqueous tape casting process. The effects of dispersant and solid loading on the rheological property of suspensions were characterized. The decomposition and sintering process for the tapes were discussed, respectively. The test results showed that compared with Triethyl phosphate, good dispersion for the dispersant OP-85 was found in the slurry, and the optimum addition reached to 0.65 wt%. The suspensions including 25 vol% and 30 vol% solid loading belonged to the classical Herschel/Bulkley model, namely exhibited obvious shear thinning behavior, which was suitable for the tape casting. The DSC and TG analysis showed that the organic additives in the tapes decomposed completely at 400°C. The bulk density of the tapes sintered at 1490°C reached 5.09 g/cm ³, nearly up to about 98% of the theoretical density. In addition, the second phase was not observed from the XRD patterns of Y ₃Fe _4.85O ₁₂ sintered tapes and the SEM images showed the sintered samples had a homogeneous microstructure.