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

Area of Science:

• Materials Science
• Solid-State Chemistry
• Luminescence

Background:

• Lanthanide-activated phosphors are crucial for understanding structure-property relationships and advancing research techniques.
• Optical thermometry requires materials with temperature-sensitive luminescence for accurate temperature measurements.

Purpose of the Study:

• To investigate the luminescence properties of Eu2+-doped Li4SrCa(SiO4)2 as a potential optical thermometric material.
• To explore the temperature-dependent emission intensities of Eu2+ ions at different sites (EuSr2+ and EuCa2+) within the crystal lattice.

Main Methods:

• Synthesis and characterization of Eu2+-doped Li4SrCa(SiO4)2.
• Measurement of luminescence spectra and intensities as a function of temperature.
• Analysis of the temperature sensitivity of Eu2+ emission.

Main Results:

• A novel evolution of Eu2+ luminescence was observed in the as-prepared sample under UV illumination and thermal treatment.
• The material demonstrated distinct temperature sensitivities for EuSr2+ and EuCa2+ emissions.
• Maximum relative sensitivities of 2.87% K-1 (at 440 K) and 1.51% K-1 (at 460 K) were achieved for the as-prepared and illuminated samples, respectively.

Conclusions:

• Eu2+-doped Li4SrCa(SiO4)2 shows significant potential as an optical thermometric material due to its temperature-dependent luminescence.
• The differential sensitivity of Eu2+ ions at different lattice sites offers a unique mechanism for optical thermometry.
• Further research into this material could lead to advancements in non-contact temperature measurement technologies.