Coatings containing the so-called cool which reflect infrared beams, besides providing greater resistance against weathering and longer lifetime, reflect a big portion of these surface-heating waves. Given the high price and great cost associated with extravagant use of cooling systems and to provide resistance against Heat island which leads to temperature difference of 10 to 15 degrees between downtown and suburbs, much research has been conducted regarding the production of these pigments. These pigments are used in coatings, materials, buildings, automobiles, fireproof colors, and military applications. Among the factors affecting the reflection of these coatings is the size and shape of their particles. This study seeks to create brown color pigment which has greater reflection than typical pigments. In this study, iron-chromium-based brown nanopigments were hydrothermally prepared in absence and presence of two kind of surfactants, with the resulting powder subjected to thermal operations so that the ions present in the combination developed a stable crystal array. Results of x-ray diffraction experiment showed spinel phase and rhombohedral structure. Examining the percentage of infrared reflection and scanning electron microscope images showed the effect of surfactant on the morphology of these pigments and increasing their reflection. Samples with finer particle sizes and the special flake form morphology and more uniform particle distribution had 20% more reflection than those with heterogeneous microstructures, and this 50% plus reflection makes their usage possible as cool pigment.
