Li4SrCa(SiO4)2:Eu2+: A Potential Temperature Sensor with Unique Optical Thermometric Properties.

Investigations on luminescence properties of lanthanide-activated phosphors are not only essential to understanding the fundamental structure-property relationship but also important to advancing the development and application of relevant research techniques. We report herein a promising optical thermometric material Eu2+-doped Li4SrCa(SiO4)2 utilizing the different sensitivities of EuSr2+ and EuCa2+ emission intensities to temperature. A unique evolution of Eu2+ luminescence in the as-prepared sample is identified under the simultaneous action of UV illumination and thermal treatment. The maximum relative sensitivities are 2.87% K-1 (at 440 K) and 1.51% K-1 (at 460 K) for the as-prepared and illuminated samples, respectively. These temperature sensing features reflect a great potential of Eu2+-doped Li4SrCa(SiO4)2 for applications in the optical thermometry field.