The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 23 3 2023 11 22 Optical and thermochromic properties of yttrium iron garnet paint Optical and thermochromic properties of yttrium iron garnet paint 67 73 3434 10.47176/ijpr.23.3.81544 FA Ali Rostamnejadi Faulty of Electromagnetics, Malek Ashtar University of Technology, Iran Mohammad Madahi Harandi Faulty of Electromagnetics, Malek Ashtar University of Technology, Iran Mohammad Jazirehpour Faulty of Electromagnetics, Malek Ashtar University of Technology, Iran Journal Article 2022 08 04 In this study, we have investigated the optical and high-temperature thermochromic properties of yttrium iron garnet powder and paint. The powders were produced using the solid-state reaction technique, and the thermochromic paint was sprayed over an Al alloy substrate. X-ray diffraction patterns, optical and field emission scanning electron microscopes, and UV-Vis and FTIR spectrophotometers were used to assess the structural, surface morphology and optical characteristics of the materials. The thermochromic characteristics of the samples were investigated by extracting the chromatic coordinates L*b*a* from digital pictures taken at temperatures ranging from 25 to 210 °C. The results reveal that when the temperature rises, the color of the paint changes from dark green to dark brown. The charge transfer between oxygen and iron ions, as well as the electron transition across the orbitals of the d layer, could be responsible for the observed reversible color change. The paint has strong thermal stability up to 350 °C which is suitable for high-temperature thermochromic applications. In this study, we have investigated the optical and high-temperature thermochromic properties of yttrium iron garnet powder and paint. The powders were produced using the solid-state reaction technique, and the thermochromic paint was sprayed over an Al alloy substrate. X-ray diffraction patterns, optical and field emission scanning electron microscopes, and UV-Vis and FTIR spectrophotometers were used to assess the structural, surface morphology and optical characteristics of the materials. The thermochromic characteristics of the samples were investigated by extracting the chromatic coordinates L*b*a* from digital pictures taken at temperatures ranging from 25 to 210 °C. The results reveal that when the temperature rises, the color of the paint changes from dark green to dark brown. The charge transfer between oxygen and iron ions, as well as the electron transition across the orbitals of the d layer, could be responsible for the observed reversible color change. The paint has strong thermal stability up to 350 °C which is suitable for high-temperature thermochromic applications. https://ijpr.iut.ac.ir/article_3434_14c879f3f5d8ed93a09f6090d77c2cc3.pdf