Abstract High near-infrared (NIR) reflectivity and infrared emissivity are desired in cooling pigments used in exterior coating of buildings. More importantly, controllable infrared emission and NIR reflectivity are needed for the next generation buildings. In this work, tunable NIR reflectivity and infrared emissivity were realized with substitutional iron-doped orthorhombic YMnO3 for the first time. The iron-doped orthorhombic YMnO3 were successfully synthesized by using a facile molten salt synthesis (MSS) method under low temperature and normal pressure. The effect of substitutional iron-doping on the microstructure, NIR reflectance and infrared radiation characteristics of orthorhombic YMnO3 were investigated. The results showed that substitutional doping of Fe ions was an effective method to control the NIR reflectivity and infrared emissivity. The emissivity of Fe ion-substituted pigmented coatings in 8-14 µm waveband (atmospheric window) was obviously increased due to the lattice distortion. Moreover, the increased amount of Mn3+-Mn4+ ions pairs in the pigments with moderate Fe ions content led to the strengthened absorption of free carrier and the further increased infrared emissivity of the pigmented coatings. Furthermore, the pigmented coatings with higher Fe ions content had enhanced reflectivity in the 1500-2200 nm waveband, since the pigments possessed well-grown and plate-shape particles. The results in this work indicated that the Fe ion-substituted orthorhombic YMnO3 pigments had promising application prospects in energy conservation of buildings by utilizing NIR shielding as well as space cooling.

中文翻译：

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可控制的近红外反射率和红外发射率与替代铁掺杂正交 YMnO3 涂层

摘要 在建筑物外墙涂料中使用的冷却颜料需要高近红外 (NIR) 反射率和红外发射率。更重要的是，下一代建筑需要可控的红外发射和近红外反射率。在这项工作中，首次用置换铁掺杂正交晶系 YMnO3 实现了可调谐的 NIR 反射率和红外发射率。在低温常压下，采用简便的熔盐合成（MSS）法成功合成了掺铁正交晶系YMnO3。研究了置换铁掺杂对正交晶系YMnO3的微观结构、近红外反射率和红外辐射特性的影响。结果表明，Fe离子的置换掺杂是控制近红外反射率和红外发射率的有效方法。由于晶格畸变，Fe离子取代颜料涂层在8-14μm波段（大气窗口）的发射率明显增加。此外，Fe离子含量适中的颜料中Mn3+-Mn4+离子对的增加导致游离载流子的吸收增强，着色涂层的红外发射率进一步增加。此外，具有较高 Fe 离子含量的着色涂层在 1500-2200 nm 波段具有增强的反射率，因为颜料具有生长良好的板状颗粒。