In this study, a series of Zn_1+xGa_2−2xSn_xO₄:1 %Cr³⁺, a %Yb³⁺, b %Er³⁺ (x = 0, 0.1, 0.3, 0.5, 0.6, 0.8, 1; a = 0.5, b = 0.1; a = 1, b = 0.1; a = 2.5, b = 0.5; a = 5, b = 0.5; a = 5, b = 1; a = 10, b = 1) (ZGSO:Cr, Yb, Er) up-converted persistent luminescence (UCPL) materials were obtained by combining the processes of up-conversion luminescence and persistent luminescence via solid-state sintering. The up-converted and persistent luminescence properties of the prepared materials, as well as the “Yb³⁺ → Er³⁺ → Cr³⁺” energy transfer mode, were analyzed under 980 nm near-infrared light. The remarkable afterglow luminescence was excited by 274 nm ultraviolet light. Furthermore, the effects of different element ratios and preparation temperatures on the structure and luminescent properties of the materials were studied. It was determined that the most suitable preparation condition for Zn₃Ga₂SnO₈:1 %Cr³⁺, 5 %Yb³⁺, 0.5 %Er³⁺ was a temperature of 1450 °C maintained for 2 h. This study describes the possibility of ZGSO:Cr, Yb, Er using for imaging, sensing, and other complex applications in biological therapy.

The reaction of stoichiometric hydroxyapatite (HAp) with different crystallinity in Mg²⁺ aqueous solution was investigated using X-ray absorption near edge structure (XANES). Crystallinity is one of important factors for the properties of HAp. Therefore, this study aimed to clarify the effect of crystallinity on the behavior of HAp in aqueous solutions. Stoichiometric HAp samples with different crystallinities were prepared using an aqueous solution precipitation method and subsequent calcination. The Mg-K XANES spectra of the HAp pellets after immersing in Mg(NO₃)₂ aqueous solution were classified into two groups: those of Mg-doped HAp and Mg(OH)₂. This difference is caused by the solubility of the HAp pellets in water, owing to their crystallinity. This result provides insights into the reaction mechanism of HAp in the human body and facilitates selection of suitable biomaterials.

To understand the effect of chemical strengthening process on irregular geometry, a partially thinned glass substrate was strengthened according to the ion-exchange conditions, and the strengthening properties and the dimensional changes of the partially thinned glass were analyzed using a surface stress meter and a 3-dimensional analyzer. The results revealed that the compressive stress (CS) measured at a thin area of the glass substrate having different thicknesses was affected by the CS of a thick zone, and consequentially the CS of the thin zone was bigger than that measured at a same thickness glass. It was also found that the dimensional changes across the thin zone after chemical strengthening were relatively big, and as a result, it caused a physical deformation on the thin area due to the interference in the thick area.