Synthesis and evaluation of ZnFe2-xAlxO4 spinel ferrite nanopigments with high NIR reflectance

In the present study, ZnFe2-xAlxO4 nano-pigments for cool coatings usage, have been successfully synthesized via polymeric precursor method. The phase analysis was carried out by X-ray diffraction (XRD). The FESEM images were used for nano-pigments grains displaying. Furthermore, UV-Vis-NIR absorption and reflectance spectra were used for absorption peaks, charge transfer, band gap and NIR solar reflectance evaluation. XRD results revealed that all the samples were in the cubic spinel structure. FESEM images displayed that the grains are homogeneously individualized. Considering of both colorimetric properties and UV-Vis-NIR reflectance, Al3+ enrichment of spinel ferrite structure resulted in enhancement of lightness, NIR solar reflectance and band gap improvement. High NIR reflectance properties with low change in host pigment color clearly highlights the potential for the utility of these pigments in cool coatings.