Preparation of three-dimensionally ordered macroporous perovskite materials

In this paper, we use La0.8Sr0.2MnO3 and La0.7Ca0.2Sr0.1MnO3 as examples to demonstrate a preparation method for three-dimensionally ordered macroporous (3DOM) perovskite thermochromic materials. Polystyrene spheres with an average diameter of 220 nm were self-assembled into a three-dimensionally ordered colloidal crystal template. A mixed metal nitrate solution prepared using La(NO3)(3)center dot 6H(2)O, Ca(NO3)(2)center dot 4H(2)O, Sr(NO3)(2), Mn(CH3COO)(2)center dot 4H(2)O and an ethanol precursor was used to fill the interstitial voids of the polystyrene colloidal crystal templates. 3DOM La0.8Sr0.2MnO3 and La0.7Ca0.2Sr0.1MnO3 materials were then obtained after the sphere templates were removed via drying and calcination. The results show that the framework of the 3DOM materials can have different thicknesses and pore shrinkage rates by varying the filling times. In addition, the Curie temperatures of the 3DOM and bulk La0.8Sr0.2MnO3 materials can be varied by altering the preparation method.