Researchers in Japan have added impurities to layered perovskite ceramics which enhances their near-infrared light reflectivity making them ideally suited to heat mitigation.
Layered perovskites like titanium-added calcium manganese oxide ceramics have attracted attention as materials that can prevent solar heat absorption by reflecting near-infrared (NIR) radiation better than commercial pigments.
However, the mechanism underlying their high NIR reflectivity had been unclear.
Researchers from the Nagoya Institute of Technology (NITech) have adopted a combination of experimental and theoretical approaches to provide useful insights into the structure, properties, and functioning of these layered perovskites that can be extended to a broad range of crystalline ceramics.
The research could be used to combat the heat island effect. Urban areas without sufficient tree cover are significantly warmer than their surroundings.
This “urban heat island” effect mainly results from an absorption of near-infrared (NIR) radiation in sunlight. NIR-reflective pigments that can mitigate such heating effects are, therefore, highly desirable.
They can be used in construction or as a thermal coating for city buildings.
Lead researcher Dr. Ryohei Oka found that novel perovskites such as titanium-added calcium manganese oxide (Ca2(Mn,Ti)O4) ceramics are much better at reflecting NIR radiation than commercially available black pigments.
“These findings take us a step closer towards unveiling the thermal shielding property of perovskite ceramics,” he said.
The Nagoya Institute of Technology (NITech) is a respected engineering institute in Japan which was established in 1949.