Dual‐mode optical thermometry based on glass‐ceramics from blast furnace slag

A series of glass ceramic samples precipitated with Ca 2 (Mg 0.5 Al 0.5 )(Si 1.5 Al 0.5 O 7 ): Yb 3+ , Er 3+ nanoparticles were synthesized by the melt quenching method to effectively recycle blast furnace slag. Their structures, morphologies, and luminescent properties were comprehensively investigated using X‐ray diffraction, transmission electron microscopy, and photoluminescence, respectively. The impact of adding Al 2 O 3 /SiO 2 to the blast furnace slag raw material on the transmittance, hardness, and luminescent properties of the glass‐ceramics was analyzed. Upon excitation with a 980 nm laser, all glass‐ceramic samples emitted strong Er 3+ upconversion luminescence at 526, 549, and 650 nm. Moreover, the addition of Yb 3+ ions significantly enhanced the luminescent intensity. A dual‐mode temperature sensor based on fluorescence intensity ratios was realized using a single luminescent center. All results indicate that the glass ceramic samples prepared from blast furnace slag are potentially promising for self‐referential optical temperature measurement.