In-situ interface engineering strategy facilitates tunable photochromism in KSr₂Nb₅O₁₅-based ceramics

With the development of related technology, the practical application scenarios put forward new requirements of multi-color and controllable modulation for inorganic photochromic materials. In this work, a novel inorganic photochromic MgNb₂O₆ ceramic has been proposed, exhibiting distinctly different photochromic behavior from KSr₂Nb₅O₁₅ ceramics. Through in-situ compositing, MgNb₂O₆ secondary phases nucleated epitaxially within the KSr₂Nb₅O₁₅ matrix, with interfacial KNbO₃ transition layers (of about 1–2 nm thickness by AC-TEM) spontaneously forming at phase boundaries, which built the specific heterojunction structure. The central positions of photochromic absorption bands could be modulated from 426 nm to 495 nm, the related color-difference values (△ Eab ) covered from 3.95 to 16.40. This work provided a novel thought for the color modulation strategy of inorganic photochromic materials.