A new perspective for the thermal degradation mechanism of blue BAM

A new thermal degradation mechanism for blue BAM (BaMgAl₁₀O₁₇:Eu²⁺) under thermal treatment in the presence of water is proposed. The water can be originated either from the thermal treatment steps, such as organic binder baking steps, or from the atmosphere under which blue BAM is being heated. Under such thermal treatment conditions, water molecules can be easily intercalated into the conduction layers of blue BAM, resulting in not only the depreciation of luminance but also in the emission color change toward green. The intercalated water molecules in the conduction layer, where Eu²⁺ ions are located along with Ba²⁺ ions, are strongly associated with Eu²⁺ ions, creating different coordination environments around Eu²⁺ ions. In this paper, the details of changes in emission behaviors along with water content in the water intercalated blue BAMs are discussed.