Novel compressive Al2O3-based seals were developed and characterized under simulated intermediate temperature solid oxide fuel cell (IT-SOFC) environment. The seals were prepared by tape casting, mainly composed of fine Al2O3 powder with various contents of fine Al powder addition. The leakage rates were determined at 800 degrees C under 0.14-0.69 MPa compressive stresses, and the stabilities were evaluated at 750 degrees C under constant 0.35 MPa compressive stress. The leakage rates at 800 degrees C were in range of 0.2-0.01 sccm cm(-1), decreasing with increasing the compressive stress and Al content; Al addition significantly improved the stability, the leakage rate with 20 wt% Al addition was as low as 0.025 sccm cm(-1) at 800 degrees C under 0.35 MPa compressive stress with a gauge pressure of 6.9 kPa, and exhibited good stability at 750 degrees C. Single cell test also confirmed the effectiveness of the tape cast Al2O3-based seal for planar IT-SOFC applications. (c) 2007 Elsevier B.V. All rights reserved.