Control of structural disorder in spinel ceramics derived from layered double hydroxides

Abstract

Spinel oxides are versatile and functional materials with physicochemical properties that are significantly influenced by their structural disorder. The transition from layered double hydroxides (LDHs) to mixed metal oxides (MMOs) containing spinel oxides is a powerful approach to create materials with tailored properties suitable for various applications. Herein, we report the control of structural ordering in spinels related to the crystallinity, cationic inversion, and coordination number of constituent atoms by varying the transformation energy. Transformation from LDHs to spinels with higher applied energy leads to higher crystallinity, lower degree of inversion, and lower ratios of low-coordinated atoms to fully coordinated atoms after treatment with acid. We provide a general framework for controlling structural ordering, that can be applied to other spinels and metal oxides. In addition, LDHs and MMOs possess many chemical and structural degrees of freedom, making it possible to create materials that suit the needs of different applications, such as memory, sensors, catalysis, and energy conversion.