Titanium Based Perovskite Materials with Nonequilibrium Surface Oxygen Vacancy Compatibly Realize Laser Stealth and Laser Protection

Laser stealth and laser protection are a contradictory due to the opposite requirement in reflectivity. Introducing nonequilibrium surface oxygen vacancy into high-reflectivity materials is a method to compatibly realize laser stealth and laser protection. Herein, nonequilibrium surface oxygen vacancy is introduced into the titanium-based perovskite materials (CaTiO 3 , SrTiO 3 , BaTiO 3 ) producing high-absorption materials with reflectivity below 10%, and the materials possess an optical transformation property. The distribution of the oxygen vacancy is characterized by TEM and EELS, and a core-shell structure is observed, with a disordered shell covering a crystalline core. Under laser irradiation, the materials can transform to high-reflectivity state and reflect most of the laser energy to prevent laser damage. Among these materials, BaTiO 3 possesses the fastest transformation rate of 2000 ms and the highest reflectivity of 70%, which is ascribed to the low thickness of the disordered shell and the fast diffusion coefficient of the oxygen atom.