Ultra-wideband low-reflectance spinel films with nanostructure prepared by in-situ one-step hydrothermal method

The ultra-wideband low-reflectance materials are ideal core materials for advanced optical instruments, which are difficult to synthesize at present. Herein, in-situ one-step hydrothermal method was firstly introduced to prepare spinel films with nanostructures on low-cost Fe-Cr alloy substrates. The film shows excellent low reflectance in the range of 0.3-2.5 mu m and 2.5-13 mu m, which are 4.34% and 4.99% respectively, due to the uniform nano-micron structure on surface. The synthesized spinel film can be an ideal candidate ultra-wideband low-reflectance material for improving high-precision for optical instruments.