Morphologically distinctive YFeO3 with near-infrared reflection and ferromagnetic characteristics

Yttrium ferrite (YFeO₃) is highly attractive as a promising multiferroic material and also has been proven to have potential in the field of near-infrared reflective cold pigments. In this work, YFeO₃ powders were fabricated via metal citrate xerogel mediated molten salt procedure at different temperatures. The complexation process of the metal citrate xerogel as a precursor was promoted by the salt medium, and the molten salt medium reduces the reaction temperature to obtain morphologically distinctive YFeO₃ without impurity. The orange YFeO₃ powders possessed outstanding near-infrared reflection characteristics and high solar reflectance. The relationship of particle size, particle shape, charge state distribution, magnetic performance and near-infrared reflection performance of YFeO₃ was investigated. Specifically, with the increase of calcining temperature, particle size increases, thereby increasing the infrared reflectivity. The rising in the amount of Fe²⁺–Fe³⁺ ion pairs increased the absorption of free carriers, thereby reducing the infrared reflectivity. The two factors contributed together to the near-infrared reflectivity, which first increased and then decreased with the increase of calcining temperature. In addition, the increase in the ratio of Fe²⁺ also hindered the super-exchange and Dzyaloshinskii–Moriya interaction of Fe–O–Fe, thereby improving of the weak-ferromagnetic behavior of YFeO₃.