Our group proposes to improve intermediate-temperature stability of BSCF by constructing high entropy perovskites. High entropy oxides bring more space for materials design in many fields. With the basic knowledge of high entropy effect that the stability of materials in thermodynamics could be improved by increasing the mixed entropy, we speculate that the phase transition of Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) at intermediate temperatures may be inhibited by improving the mixed entropy.
In this paper, we disclosed that compared with BSCF, doping elements at A site (HEBSCF-A), at B site (HEBSCF-B) or at both sites (HEBSCF-AB) can improve the mixed entropy of perovskite oxides. Among the three doped BSCF, HEBSCF-AB has the highest mixed entropy of 2.04R and shows stable oxygen permeation flux at 750 and 800 °C up to 300 h. No phase transition was observed on HEBSCF-AB after the long-term tests at intermediate-temperatures, indicating the high entropy stabilization effect works for the improvement of the oxygen permeation stability of MIEC membranes by inhibiting phase transition. This work has been published in Journal of Membrane Science Letters.
The article links:https://doi.org/10.1016/j.memlet.2022.100026